ABSTRACT
The recent global outbreak of mpox, caused by monkeypox virus (MPV) emerged in Europe in 2022 and rapidly spread to over 40 countries. The Americas are currently facing the highest impact, reporting over 50,000 cases by early 2023. In this study, we analyzed 880 MPV isolates worldwide to gain insights into the evolutionary patterns and initial introduction events of the virus in Mexico. We found that MPV entered Mexico on multiple occasions, from the United Kingdom, Portugal, and Canada, and subsequently spread locally in different regions of Mexico. Additionally, we show that MPV has an open pangenome, highlighting the role of gene turnover in shaping its genomic diversity, rather than single-nucleotide polymorphisms (SNPs), which do not contribute significantly to genome diversity. Although the genome contains multiple SNPs in coding regions, these remain under purifying selection, suggesting their evolutionary conservation. One notable exception is amino acid position 63 of the protein encoded by the Cop-A4L gene, which is intricately related to viral maturity, which we found to be under strong positive selection. Ancestral state reconstruction indicated that the ancestral state at position 63 corresponds to the amino acid valine, which is present only in isolates of clade I. However, the isolates from the current outbreak contained threonine at position 63. Our findings contribute new information about the evolution of monkeypox virus.
Subject(s)
Mpox (monkeypox) , Humans , Monkeypox virus/genetics , Mexico/epidemiology , Phylogeny , Amino Acids/genetics , Disease OutbreaksABSTRACT
Schistosoma mansoni is a parasitic flatworm that causes a human disease called schistosomiasis, or bilharzia. At the genomic level, S. mansoni is AT-rich, but has some compositional heterogeneity. Indeed, some regions of its genome are GC-rich, mainly in the regions located near the extreme ends of the chromosomes. Recently, we showed that, despite the strong bias towards A/T ending codons, highly expressed genes tend to use GC-rich codons. Here, we address the following question: are highly expressed sequences biased in their amino acid frequencies? Our analyses show that these sequences in S. mansoni, as in species ranging from bacteria to human, are strongly biased in nucleotide composition. Highly expressed genes tend to use GC-rich codons (in the first and second codon positions), which code the energetically cheapest amino acids. Therefore, we conclude that amino acid usage, at least in highly expressed genes, is strongly shaped by natural selection to avoid energetically expensive residues. Whether this is an adaptation to the parasitic way of life of S. mansoni, is unclear since the same pattern occurs in free-living species.
Subject(s)
Platyhelminths , Animals , Humans , Platyhelminths/genetics , Schistosoma mansoni/genetics , Amino Acids/genetics , Codon , BacteriaABSTRACT
A previously uncharacterized torradovirus species infecting potatoes was detected by high-throughput sequencing from field samples from Peru and in customs intercepts in potato tubers that originated from South America in the United States of America and the Netherlands. This new potato torradovirus showed high nucleotide sequence identity to an unidentified isometric virus (SB26/29), which was associated with a disease named potato rugose stunting in southern Peru characterized over two decades ago. Thus, this virus is tentatively named potato rugose stunting virus (PotRSV). The genome of PotRSV isolates sequenced in this study were composed of two polyadenylated RNA segments. RNA1 ranges from 7,086 to 7,089 nt and RNA2 from 5,228 to 5,230 nt. RNA1 encodes a polyprotein containing the replication block (helicase-protease-polymerase), whereas RNA2 encodes a polyprotein cleaved into a movement protein and the three capsid proteins (CPs). Pairwise comparison among PotRSV isolates revealed amino acid identity values greater than 86% in the protease-polymerase (Pro-Pol) region and greater than 82% for the combined CPs. The closest torradovirus species, squash chlorotic leaf spot virus, shares amino acid identities of â¼58 and â¼41% in the Pro-Pol and the combined CPs, respectively. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
Subject(s)
Solanum tuberosum , Solanum tuberosum/genetics , RNA, Viral/genetics , Peru , Genome, Viral , Plant Diseases , Peptide Hydrolases/genetics , Polyproteins/genetics , Amino Acids/genetics , Growth Disorders/geneticsABSTRACT
The standard genetic code determines that in most species, including viruses, there are 20 amino acids that are coded by 61 codons, while the other three codons are stop triplets. Considering the whole proteome each species features its own amino acid frequencies, given the slow rate of change, closely related species display similar GC content and amino acids usage. In contrast, distantly related species display different amino acid frequencies. Furthermore, within certain multicellular species, as mammals, intragenomic differences in the usage of amino acids are evident. In this communication, we shall summarize some of the most prominent and well-established factors that determine the differences found in the amino acid usage, both across evolution and intragenomically.
Subject(s)
Amino Acids , Genetic Code , Animals , Amino Acids/genetics , Codon/genetics , Base Composition , Proteome/genetics , Evolution, Molecular , Mammals/geneticsABSTRACT
Bovine papillomaviruses (BPVs) exhibit a high degree of genetic variability, and several viral types have been identified based on analysis of the L1 gene. The L1 is the main capsid protein and the main target for neutralizing antibodies. We performed a retrospective study on BPVs circulating in Rio Grande do Sul state, Southern Brazil, in 2016-2020. DNA from 43 bovine papilloma samples were amplified using two degenerate primer sets - FAP59/64 and MY09/11 - targeting the L1 region, and analyzed for phylogeny, mixed BPV infections (coinfections) and amino acid (aa) sequences. We also performed an in silico analysis with 114 BPV L1 sequences from the GenBank database to assess the agreement between the phylogeny obtained based on complete L1 sequences versus that based on the region amplified using the FAP59/64 and MY09/11 primer sets. Considering single and coinfections, we identified 31 BPV-1 (31/43; 72.1%), 27 BPV-2 (27/43; 62.8%) and 4 BPV-6 (4/43; 9.3%). Coinfections with BPV-1 and BPV-2 were observed in 61.3% of the samples. Our results are supported by in silico analyses that demonstrate that the classification using FAP59/64 or MY09/11 matches the complete L1 results, except for BPV-17 and -18, which may be mistakenly classified depending on the primers used. Furthermore, we found unique or rare amino acids in at least one L1 sequence of each BPV type identified in our study, some of which have been identified previously in papillomavirus epitopes, suggesting immune-mediated selection. Finally, our study provides an overview of BPVs circulating in Southern Brazil over the last five years and point to the combined use of primers FAP59/64 and MY09/11 for analysis of BPV coinfections and putative epitopes.
Subject(s)
Bovine papillomavirus 1 , Cattle Diseases , Coinfection , Papillomavirus Infections , Animals , Cattle , Papillomavirus Infections/epidemiology , Papillomavirus Infections/veterinary , Phylogeny , Brazil/epidemiology , Amino Acids/genetics , Retrospective Studies , DNA, Viral/genetics , Papillomaviridae/genetics , Cattle Diseases/epidemiologyABSTRACT
WRKY transcription factors (TFs) play key roles in plant defense responses through phytohormone signaling pathways. However, their functions in tropical fruit crops, especially in banana, remain largely unknown. Several WRKY genes from the model plants rice (OsWRKY45) and Arabidopsis (AtWRKY18, AtWRKY60, AtWRKY70) have shown to be attractive TFs for engineering disease resistance. In this study, we isolated four banana cDNAs (MaWRKY18, MaWRKY45, MaWRKY60, and MaWRKY70) with homology to these rice and ArabidopsisWRKY genes. The MaWRKY cDNAs were isolated from the wild banana Musa acuminata ssp. malaccensis, which is resistant to several diseases of this crop and is a progenitor of most banana cultivars. The deduced amino acid sequences of the four MaWRKY cDNAs revealed the presence of the conserved WRKY domain of ~60 amino acids and a zinc-finger motif at the N-terminus. Based on the number of WRKY repeats and the structure of the zinc-finger motif, MaWRKY18 and MaWRKY60 belong to group II of WRKY TFs, while MaWRKY45 and MaWRKY70 are members of group III. Their corresponding proteins were located in the nuclei of onion epidermal cells and were shown to be functional TFs in yeast cells. Moreover, expression analyses revealed that the majority of these MaWRKY genes were upregulated by salicylic acid (SA) or methyl jasmonate (MeJA) phytohormones, although the expression levels were relatively higher with MeJA treatment. The fact that most of these banana WRKY genes were upregulated by SA or MeJA, which are involved in systemic acquired resistance (SAR) or induced systemic resistance (ISR), respectively, make them interesting candidates for bioengineering broad-spectrum resistance in this crop.
Subject(s)
Arabidopsis , Musa , Musa/genetics , Plant Growth Regulators/pharmacology , Plant Growth Regulators/metabolism , Transcription Factors/metabolism , Gene Expression Regulation, Plant , Plant Proteins/metabolism , Salicylic Acid/pharmacology , Arabidopsis/genetics , Amino Acids/genetics , Zinc/metabolismABSTRACT
Mato Grosso (MT) State is part of central western Brazil and has a tropical permissive environment that favors arbovirus outbreaks. A metagenomic approach was used to identify viral genomes in seven pools of serum from patients (n=65) with acute febrile disease. Seven chikungunya virus (CHIKV) genomes were determined, showing four amino acid changes found only in CHIKV genomes obtained in MT since 2018: nsP2:T31I, nsP3: A388V, E3:T201I and E3:H57R, in addition to other mutations in E1, nsP2 and nsP4. Six parvovirus B19 (B19V) genotype I genomes (4771-5131 nt) showed four aa alterations (NS1:N473D, R579Q; VP1:I716T; and 11 kDa:V44A) compared to most similar B19V from the USA. Coinfection between CHIKV and B19V was evidenced in 22/65 (33.8%) patients by RTâPCR and PCR, respectively. Other viruses found in these pools include human pegivirus C, torque teno virus 3, an unclassified TTV and torque teno mini virus. Metagenomics represents a useful approach to detect viruses in the serum of acute febrile patients suspected of arbovirus disease.
Subject(s)
Chikungunya Fever , Chikungunya virus , Viruses , Humans , Amino Acids/genetics , Brazil/epidemiology , Chikungunya Fever/epidemiology , Chikungunya virus/genetics , Fever , Genotype , Mutation , Phylogeny , Genome, ViralABSTRACT
Yellow fever virus (YFV) caused an outbreak in the Brazilian Southeast from 2016 to 2019, of the most significant magnitude since the 1900s. An investigation of the circulating virus revealed that most of the genomes detected in this period carried nine unique amino acid polymorphisms, with eight located in the non-structural proteins NS3 and NS5, which are pivotal for viral replication. To elucidate the effect of these amino acid changes on viral infection, we constructed viruses carrying amino acid alterations in NS3 and NS5, performed infection in different cells, and assessed their neurovirulence in BALB/c mice and infected AG129 mice. We observed that the residues that compose the YFV 2016-2019 molecular signature in the NS5 protein might have been related to an attenuated phenotype, and that the alterations in the NS3 protein only slightly affected viral infection in AG129 mice, increasing to a low extent the mortality rate of these animals. These results contributed to unveiling the role of specific naturally occurring amino acid changes in the circulating strain of YFV in Brazil.
Subject(s)
Yellow Fever , Amino Acids/genetics , Animals , Brazil/epidemiology , Disease Outbreaks , Mice , Phenotype , Yellow Fever/epidemiology , Yellow fever virus/geneticsABSTRACT
Bat coronaviruses (Bat-CoVs) represent around 35% of all virus genomes described in bats. Brazil has one of the highest mammal species diversity, with 181 species of bats described so far. However, few Bat-CoV surveillance programmes were carried out in the country. Thus, our aim was to jevaluate the Bat-CoV diversity in the Atlantic Forest, the second biome with the highest number of bat species in Brazil. We analysed 456 oral and rectal swabs and 22 tissue samples from Atlantic Forest bats, detecting Alphacoronavirus in 44 swab samples (9.6%) targeting the RdRp gene from seven different bat species, three of which have never been described as Bat-CoV hosts. Phylogenetic analysis of the amino acid (aa) sequences coding the RdRp gene grouped the sequences obtained in our study with Bat-CoV previously detected in identical or congeneric bat species, belonging to four subgenera, with high aa identity (over 90%). The RdRp gene was also detected in three tissue samples from Diphylla ecaudata and Sturnira lilium, and the partial S gene was successfully sequenced in five tissues and swab samples of D. ecaudata. The phylogenetic analysis based on the partial S gene obtained here grouped the sequence of D. ecaudata with CoV from Desmodus rotundus previously detected in Peru and Brazil, belonging to the Amalacovirus subgenus, with aa identity ranging from 73.6% to 88.8%. Our data reinforce the wide distribution of Coronaviruses in bats from Brazil and the novelty of three bats species as Bat-CoV hosts and the co-circulation of four Alphacoronavirus subgenera in Brazil.
Subject(s)
Alphacoronavirus , Chiroptera , Coronavirus Infections , Coronavirus , Alphacoronavirus/genetics , Amino Acids/genetics , Animals , Brazil/epidemiology , Coronavirus/genetics , Coronavirus Infections/veterinary , Forests , Genetic Variation , Genome, Viral , Phylogeny , RNA-Dependent RNA PolymeraseABSTRACT
Glutathione peroxidase 3 (GPx3) is the only extracellular selenoprotein (Sel) that enzymatically reduces H2O2 to H2O and O2. Two GPx3 (CqGPx3) cDNAs were characterized from crayfish Cherax quadricarinatus. The nerve cord CqGPx3a isoform encodes for a preprotein containing an N-terminal signal peptide of 32 amino acid residues, with the mature Sel region of 192 residues and a dispensable phosphorylation domain of 36 residues. In contrast, the pereiopods CqGPx3b codes for a precursor protein with 19 residues in the N-terminal signal peptide, then the mature 184 amino acid residues protein and finally a Pro-rich peptide of 42 residues. CqGPx3 are expressed in cerebral ganglia, pereiopods and nerve cord. CqGPx3a is expressed mainly in cerebral ganglia, antennulae and nerve cord, while CqGPx3b was detected mainly in pereiopods. CqGPx3a expression increases with high temperature and hypoxia; meanwhile, CqGPx3b is not affected. We report the presence and differential expression of GPx3 isoforms in crustacean tissues in normal conditions and under stress for high temperature and hypoxia. The two isoforms are tissue specific and condition specific, which could indicate an important role of CqGPx3a in the central nervous system and CqGPx3b in exposed tissues, both involved in different responses to environmental stressors.
Subject(s)
Astacoidea , Selenium , Amino Acids/genetics , Animals , Astacoidea/genetics , Astacoidea/metabolism , Cloning, Molecular , DNA, Complementary/genetics , Hydrogen Peroxide/metabolism , Hypoxia , Protein Isoforms/genetics , Protein Isoforms/metabolism , Protein Sorting Signals/genetics , Selenium/metabolism , TemperatureABSTRACT
The function of a protein is strongly dependent on its structure. During evolution, proteins acquire new functions through mutations in the amino-acid sequence. Given the advance in deep mutational scanning, recent findings have found functional change to be position dependent, notwithstanding the chemical properties of mutant and mutated amino acids. This could indicate that structural properties of a given position are potentially responsible for the functional relevance of a mutation. Here, we looked at the relation between structure and function of positions using five proteins with experimental data of functional change available. In order to measure structural change, we modeled mutated proteins via amino-acid networks and quantified the perturbation of each mutation. We found that structural change is position dependent, and strongly related to functional change. Strong changes in protein structure correlate with functional loss, and positions with functional gain due to mutations tend to be structurally robust. Finally, we constructed a computational method to predict functionally sensitive positions to mutations using structural change that performs well on all five proteins with a mean precision of 74.7% and recall of 69.3% of all functional positions.
Subject(s)
Amino Acid Sequence , Amino Acids , Evolution, Molecular , Models, Molecular , Mutation , Proteins , Amino Acids/chemistry , Amino Acids/genetics , Protein Conformation , Proteins/chemistry , Proteins/geneticsABSTRACT
As the SARS-CoV-2 has spread and the pandemic has dragged on, the virus continued to evolve rapidly resulting in the emergence of new highly transmissible variants that can be of public health concern. The evolutionary mechanisms that drove this rapid diversity are not well understood but neutral evolution should open the first insight. The neutral theory of evolution states that most mutations in the nucleic acid sequences are random and they can be fixed or disappear by purifying selection. Herein, we performed a neutrality test to better understand the selective pressures exerted over SARS-CoV-2 spike protein from homologue proteins of Betacoronavirus, as well as to the spikes from human clinical isolates of the virus. Specifically, Tyr and Asn have higher occurrence rates on the Receptor Binding Domain (RBD) and in the overall sequence of spike proteins of Betacoronavirus, whereas His and Arg have lower occurrence rates. The in vivo evolutionary phenomenon of SARS-CoV-2 shows that Glu, Lys, Phe, and Val have the highest probability of occurrence in the emergent viral particles. Amino acids that have higher occurrence than the expected by the neutral control, are favorable and are fixed in the sequence while the ones that have lower occurrence than expected, influence the stability and/or functionality of the protein. Our results show that most unique mutations either for SARS-CoV-2 or its variants of health concern are under selective pressures, which could be related either to the evasion of the immune system, increasing the virus' fitness or altering protein - protein interactions with host proteins. We explored the consequences of those selected mutations in the structure and protein - protein interaction with the receptor. Altogether all these forces have shaped the spike protein and the continually evolving variants.
Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Amino Acids/chemistry , Amino Acids/genetics , Angiotensin-Converting Enzyme 2/chemistry , Betacoronavirus/genetics , Evolution, Molecular , Genetic Drift , Glycosylation , Humans , Models, Theoretical , Mutation , Protein Binding/genetics , Spike Glycoprotein, Coronavirus/chemistryABSTRACT
Proteins can evolve by accumulating changes on amino acid sequences. These changes are mainly caused by missense mutations on its DNA coding sequences. Mutations with neutral or positive effects on fitness can be maintained while deleterious mutations tend to be eliminated by natural selection. Amino acid changes are influenced by the biophysical, chemical, and biological properties of amino acids. There is a multiplicity of amino acid properties that can influence the function and expression of proteins. Amino acid properties can be expressed into numerical indexes, which can help to predict functional and structural aspects of proteins and allow statistical inferences of selection pressure on amino acid usage. The accuracy of these analyses may be compromised by the existence of several numerical indexes that measure the same amino acid property, and the lack of objective parameters to determine the most accurate and biologically relevant index. In the present study, the gradient consistency test was used in order to estimate the magnitude of directional selection imparted by amino acid biochemical and biophysical properties on protein evolution.
Subject(s)
Amino Acids , Evolution, Molecular , Amino Acid Sequence , Amino Acids/genetics , Eukaryotic Cells , Selection, GeneticABSTRACT
The majority of DNA polymerases (DNAPs) are specialized enzymes with specific roles in DNA replication, translesion DNA synthesis (TLS), or DNA repair. The enzymatic characteristics to perform accurate DNA replication are in apparent contradiction with TLS or DNA repair abilities. For instance, replicative DNAPs incorporate nucleotides with high fidelity and processivity, whereas TLS DNAPs are low-fidelity polymerases with distributive nucleotide incorporation. Plant organelles (mitochondria and chloroplast) are replicated by family-A DNA polymerases that are both replicative and TLS DNAPs. Furthermore, plant organellar DNA polymerases from the plant model Arabidopsis thaliana (AtPOLIs) execute repair of double-stranded breaks by microhomology-mediated end-joining and perform Base Excision Repair (BER) using lyase and strand-displacement activities. AtPOLIs harbor three unique insertions in their polymerization domain that are associated with TLS, microhomology-mediated end-joining (MMEJ), strand-displacement, and lyase activities. We postulate that AtPOLIs are able to execute those different functions through the acquisition of these novel amino acid insertions, making them multifunctional enzymes able to participate in DNA replication and DNA repair.
Subject(s)
DNA Repair/physiology , DNA-Directed DNA Polymerase/genetics , Organelles/enzymology , Plant Proteins/genetics , Amino Acids/genetics , Amino Acids/metabolism , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , DNA End-Joining Repair/physiology , DNA-Directed DNA Polymerase/metabolism , Evolution, Molecular , Plant Proteins/metabolismABSTRACT
The Human Immunodeficiency Virus Type I (HIV-1) subtype B comprises approximately 10% of all HIV infections in the world. The HIV-1 subtype B epidemic comprehends a pandemic variant (named BPANDEMIC) disseminated worldwide and non-pandemic variants (named BCAR) that are mostly restricted to the Caribbean. The goal of this work was the identification of amino acid signatures (AAs) characteristic to the BCAR and BPANDEMIC variants. To this end, we analyzed HIV-1 subtype B full-length (n = 486) and partial (n = 814) genomic sequences from the Americas classified within the BCAR and BPANDEMIC clades and reconstructed the sequences of their most recent common ancestors (MRCA). Analysis of contemporary HIV-1 sequences revealed 13 AAs between BCAR and BPANDEMIC variants (four on Gag, three on Pol, three on Rev, and one in Vif, Vpu, and Tat) of which only two (one on Gag and one on Pol) were traced to the MRCA. All AAs correspond to polymorphic sites located outside essential functional proteins domains, except the AAs in Tat. The absence of stringent AAs inherited from their ancestors between modern BCAR and BPANDEMIC variants support that ecological factors, rather than viral determinants, were the main driving force behind the successful spread of the BPANDEMIC strain.
Subject(s)
Amino Acids/genetics , HIV-1/genetics , Amino Acid Motifs , HIV Infections/epidemiology , HIV Seropositivity/epidemiology , HIV-1/pathogenicity , Humans , Pandemics , Phylogeny , Spatio-Temporal AnalysisABSTRACT
An outbreak of atypical pneumonia caused by a novel Betacoronavirus (ßCoV), named SARS-CoV-2 has been declared a public health emergency of international concern by the World Health Organization. In order to gain insight into the emergence, evolution and adaptation of SARS-CoV-2 viruses, a comprehensive analysis of genome composition and codon usage of ßCoV circulating in China was performed. A biased nucleotide composition was found for SARS-CoV-2 genome. This bias in genomic composition is reflected in its codon and amino acid usage patterns. The overall codon usage in SARS-CoV-2 is similar among themselves and slightly biased. Most of the highly frequent codons are A- and U-ending, which strongly suggests that mutational bias is the main force shaping codon usage in this virus. Significant differences in relative synonymous codon usage frequencies among SARS-CoV-2 and human cells were found. These differences are due to codon usage preferences.
Subject(s)
Betacoronavirus/classification , Betacoronavirus/genetics , Codon Usage/genetics , Communicable Diseases, Emerging/virology , Gene Expression Regulation, Viral/genetics , Genome, Viral/genetics , Genomics , Amino Acids/genetics , Animals , Betacoronavirus/isolation & purification , China/epidemiology , Chiroptera/virology , Coronavirus Infections/epidemiology , Coronavirus Infections/veterinary , Coronavirus Infections/virology , Evolution, Molecular , Ferrets/virology , Humans , Mutagenesis/genetics , Open Reading Frames/genetics , SARS-CoV-2 , Viverridae/virologyABSTRACT
BACKGROUND: The enzyme farnesyl diphosphate synthase (FPPS) is positioned in the intersection of different sterol biosynthesis pathways such as those producing isoprenoids, dolichols and ergosterol. FPPS is ubiquitous in eukaryotes and is inhibited by nitrogen-containing bisphosphonates (N-BP). N-BP activity and the mechanisms of cell death as well as damage to the ultrastructure due to N-BP has not yet been investigated in Leishmania infantum and Giardia. Thus, we evaluated the effect of N-BP on cell viability and ultrastructure and then performed structural modelling and phylogenetic analysis on the FPPS enzymes of Leishmania and Giardia. METHODS: We performed multiple sequence alignment with MAFFT, phylogenetic analysis with MEGA7, and 3D structural modelling for FPPS with Modeller 9.18 and on I-Tasser server. We performed concentration curves with N-BP in Leishmania promastigotes and Giardia trophozoites to estimate the IC50via the MTS/PMS viability method. The ultrastructure was evaluated by transmission electron microscopy, and the mechanism of cell death by flow cytometry. RESULTS: The nitrogen-containing bisphosphonate risedronate had stronger anti-proliferative activity in Leishmania compared to other N-BPs with an IC50 of 13.8 µM, followed by ibandronate and alendronate with IC50 values of 85.1 µM and 112.2 µM, respectively. The effect of N-BPs was much lower on trophozoites of Giardia than Leishmania (IC50 of 311 µM for risedronate). Giardia treated with N-BP displayed concentric membranes around the nucleus and nuclear pyknosis. Leishmania had mitochondrial swelling, myelin figures, double membranes, and plasma membrane blebbing. The same population labelled with annexin-V and 7-AAD had a loss of membrane potential (TMRE), indicative of apoptosis. Multiple sequence alignments and structural alignments of FPPS proteins showed that Giardia and Leishmania FPPS display low amino acid identity but possess the conserved aspartate-rich motifs. CONCLUSIONS: Giardia and Leishmania FPPS enzymes are phylogenetically distant but display conserved protein signatures. The N-BPs effect on FPPS was more pronounced in Leishmania than Giardia. This might be due to general differences in metabolism and differences in the FPPS catalytic site.
Subject(s)
Cell Proliferation/drug effects , Diphosphonates/pharmacology , Geranyltranstransferase/chemistry , Giardia/enzymology , Giardia/ultrastructure , Leishmania/enzymology , Leishmania/ultrastructure , Amino Acids/genetics , Cell Death/drug effects , Cell Survival/drug effects , Geranyltranstransferase/antagonists & inhibitors , Giardia/drug effects , Inhibitory Concentration 50 , Leishmania/drug effects , Microscopy, Electron, Transmission , Phylogeny , Sequence Alignment , Structure-Activity RelationshipABSTRACT
The continuous search for novel enzyme backbones and the engineering of already well studied enzymes for biotechnological applications has become an increasing challenge, especially by the increasing potential diversity space provided by directed enzyme evolution approaches and the demands of experimental data generated by rational design of enzymes. In this work, we propose a semi-rational mutational strategy focused on introducing diversity in structurally variable regions in enzymes. The identified sequences are subjected to a progressive deletion of two amino acids and the joining residues are subjected to saturation mutagenesis using NNK degenerate codons. This strategy offers a novel library diversity approach while simultaneously decreasing enzyme size in the variable regions. In this way, we intend to identify and reduce variable regions found in enzymes, probably resulting from neutral drift evolution, and simultaneously studying the functional effect of said regions. This strategy was applied to Bacillus. subtilis lipase A (BSLA), by selecting and deleting six variable enzyme regions (named regions 1 to 6) by the deletion of two amino acids and additionally randomizing the joining amino acid residues. After screening, no active variants were found in libraries 1% and 4%, 15% active variants were found in libraries 2% and 3%, and 25% for libraries 5 and 6 (n = 3000 per library, activity detected using tributyrin agar plates). Active variants were assessed for activity in microtiter plate assay (pNP-butyrate), thermal stability, substrate preference (pNP-butyrate, -palmitate), and compared to wildtype BSLA. From these analyses, variant P5F3 (F41L-ΔW42-ΔD43-K44P), from library 3 was identified, showing increased activity towards longer chain p-nitrophenyl fatty acid esters, when compared to BSLA. This study allowed to propose the targeted region 3 (positions 40-46) as a potential modulator for substrate specificity (fatty acid chain length) in BSLA, which can be further studied to increase its substrate spectrum and selectivity. Additionally, this variant showed a decreased thermal resistance but interestingly, higher isopropanol and Triton X-100 resistance. This deletion-randomization strategy could help to expand and explore sequence diversity, even in already well studied and characterized enzyme backbones such as BSLA. In addition, this strategy can contribute to investigate and identify important non-conserved regions in classic and novel enzymes, as well as generating novel biocatalysts with increased performance in specific processes, such as enzyme immobilization.
Subject(s)
Bacillus subtilis/genetics , Fatty Acids/metabolism , Protein Engineering/methods , Sterol Esterase/genetics , Amino Acids/genetics , Bacillus subtilis/enzymology , Bacillus subtilis/metabolism , Binding Sites , Gene Library , Hydrolysis , Molecular Docking Simulation , Molecular Dynamics Simulation , Mutagenesis, Site-Directed , Protein Conformation , Sequence Deletion/genetics , Sterol Esterase/metabolism , Substrate Specificity/geneticsABSTRACT
Chikungunya virus (CHIKV), a positive-sense, single-stranded RNA virus in the family Togaviridae, is transmitted by Aedes mosquitoes. Of three known CHIKV genotypes, the Asian genotype was introduced into the Caribbean islands and rapidly spread throughout Central and South Americas. We previously found patients with symptoms compatible with chikungunya fever in 2014-2015 in Aruba, a Caribbean island of 180â¯km2. We here describe the full genome sequences of eight CHIKV strains isolated from patient sera of the Aruban outbreak. Phylogenetic analysis revealed that two closely related but distinct lineages of Asian-genotype CHIKV circulated simultaneously during the epidemic in 2014-2015. These results suggested that CHIKV was introduced into Aruba more than once in a short period, reflecting the importance of Aruba as a travel hub within the region.
Subject(s)
Chikungunya Fever/epidemiology , Chikungunya Fever/virology , Chikungunya virus/genetics , 3' Untranslated Regions , Amino Acids/genetics , Aruba/epidemiology , Chikungunya virus/isolation & purification , Disease Outbreaks , Genetic Variation , Humans , PhylogenyABSTRACT
transporte de los aminoácidos. Los síntomas pueden ser agudos en estado de catabolismo, donde se origina un aumento de los niveles de aminoácidos. Las manifestaciones clínicas van a depender de la cantidad y toxicidad de los metabolitos acumulados o de la importancia del producto deficiente. Estas enfermedades pueden detectarse mediante el análisis del perfil de aminoácidos en diferentes fluidos biológicos y del perfil de ácidos orgánicos en orina. Su diagnóstico, manejo y tratamiento es complejo, por lo que requiere de un conocimiento amplio y experiencia por parte del personal médico.Objetivo: Proponer una guía con recomendaciones para el adecuado diagnóstico clínico y bioquímico de las aminoacidopatías.Métodos: Se consultaron varias fuentes especializadas y plataformas de revistas médicas internacionales, de sociedades científicas internacionales, sitios web nacionales e internacionales y bases de datos (PubMed, MedlinePlus, Medline,) de los últimos 10 años. Se emplearon 10 descriptores relacionados con el objetivo del trabajo; y se tuvieron en cuenta los criterios de los expertos con más experiencia en el diagnóstico, tratamiento y manejo de los errores innatos del metabolismo en Cuba.Resultados: Se elaboró un documento donde se recogen recomendaciones prácticas dirigidas al personal médico, que garantice el diagnóstico clínico-bioquímico de las aminoacidopatías.Conclusiones: Conocer y aplicar estas recomendaciones garantizará el diagnóstico rápido y certero de estas enfermedades complejas...(AU)