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1.
Environ Monit Assess ; 195(7): 827, 2023 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-37294356

RESUMO

The Chir-Pine (Pinus roxburghii) and Banj-Oak (Quercus leucotrichophora)-dominated ecosystems of central Himalaya provide significant green services. However, responses of these ecosystems, with respect to ecosystem carbon flux variability, to changing microclimate are not yet studied. Since quantification of ecosystem responses to fluctuation in the microclimate, particularly rainfall, is expected to be beneficial for management of these ecosystems, this study aims (i) to quantify and compare amplitude of rainfall-induced change in the carbon fluxes of Chir-Pine and Banj-Oak-dominated ecosystems using wavelet methods, and (ii) to quantify and compare dissimilarities in the ecosystem exchanges due to varying rainfall spell and amount. Eddy covariance-based continuous daily micrometeorological and flux data, during the 2016-2017 monsoon seasons (total 244 days, 122 days of June-September), from two sites in Uttarakhand, India, are used for this purpose. We find that both Chir-Pine and Banj-Oak-dominated ecosystems are the sinks of carbon, and Chir-Pine-dominated ecosystem sequesters around 1.8 times higher carbon than the Banj-Oak. A systematic enhancement in the carbon assimilation of the Chir-Pine-dominated ecosystem is noted with increasing rainfall spell following a statistically significant power-law relationship. We have also identified a rainfall amount threshold for Chir-Pine and Banj-Oak-dominated ecosystems (10 ± 0.7 and 17 ± 1.2 mm, respectively) that resulted in highest ecosystem carbon assimilation in monsoon. The general inference of this study accentuates that Banj-Oak-dominated ecosystem is more sensitive to maximum rain within a spell whereas the Chir-Pine-dominated ecosystem is more responsive to increasing rainfall spell duration.


Assuntos
Pinus , Quercus , Ecossistema , Quercus/fisiologia , Estações do Ano , Carbono , Árvores/fisiologia , Monitoramento Ambiental , Florestas
2.
Genomics ; 111(4): 696-699, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-29665417

RESUMO

Glaucoma is the second leading cause of blindness after cataract and is heterogeneous in nature. Employing a genetic approach for the detection of the diseased condition provides an advantage that the gene responsible for the disease can be identified by genetic test. The availability of predictive tests based on the published literature would provide a mechanism for early detection and treatment. The genotype and phenotype information could be a valuable source for predicting the risk of the disease. To this end, a web server has been developed, based on the genotype and phenotype of myocilin mutation, which were identified by familial linkage analysis and case studies. The proposed web server provides clinical data and severity index for a given mutation. The server has several useful options to help clinicians and researchers to identify individuals at a risk of developing the disease. Glaucoma Pred server is available at http://bioserver1.physics.iisc.ac.in/myocilin.


Assuntos
Proteínas do Citoesqueleto/genética , Proteínas do Olho/genética , Glaucoma de Ângulo Aberto/genética , Glicoproteínas/genética , Fenótipo , Polimorfismo Genético , Software , Genótipo , Glaucoma de Ângulo Aberto/epidemiologia , Glaucoma de Ângulo Aberto/patologia , Humanos
3.
J Natl Med Assoc ; 111(1): 103-117, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30078757

RESUMO

INTRODUCTION: The World Health Organization (WHO) has been asserting the importance of health care in today's world. The objective of this research is to find out the type of medication that needs to be provided to the people at early stages to prevent behavioural risk factors. The health department of United States has a great vision to improve the immune system of the people and has taken measures to do the same through a Behavioural Risk Factor Surveillance System (BRFSS). This research aims to prevent behavioural risk factors by predictive analysis using the above mentioned dataset from the Centres for Disease Control and Prevention (CDC). METHODOLOGY: The methods of ensemble classification and clustering is applied on the dataset, pre and post weighted classification, thereby classifying and prescribing the type of healthcare required for people exhibiting behaviours such as obesity, nutrition and physical activity. RESULTS AND DISCUSSION: This analyses help improve the quality of health of the citizens. In an extensive study, it was observed that the result obtained was 92.87% accurate.


Assuntos
Sistema de Vigilância de Fator de Risco Comportamental , Análise por Conglomerados , Adolescente , Adulto , Idoso , Alabama/epidemiologia , Interpretação Estatística de Dados , Conjuntos de Dados como Assunto , Exercício Físico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação Nutricional , Obesidade/epidemiologia , Obesidade/prevenção & controle , Vigilância da População , Fatores de Risco , Comportamento de Redução do Risco , Fatores Socioeconômicos , Adulto Jovem
4.
Genomics ; 102(4): 403-8, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23880222

RESUMO

Genomic sequences are far from being random but are made up of systematically ordered and information rich patterns. These repeated sequence patterns have been vastly utilized for their fundamental importance in understanding the genome function and organization. To this end, a comprehensive toolkit, RepEx, has been developed which extracts repeat (inverted, everted and mirror) patterns from the given genome sequence(s) without any constraints. The toolkit can also be used to fetch the inverted repeats present in the protein sequence(s). Further, it is capable of extracting exact and degenerate repeats with a user defined spacer intervals. It is remarkably more precise and sensitive when compared to the existing tools. An example with comprehensive case studies and a performance evaluation of the proposed toolkit has been presented to authenticate its efficiency and accuracy.


Assuntos
Biologia Computacional/métodos , Sequências Repetidas Invertidas , Sequências Repetitivas de Aminoácidos , Sequências de Repetição em Tandem , Sequência de Aminoácidos , Sequência de Bases , Genoma , Humanos , Dados de Sequência Molecular , Reprodutibilidade dos Testes , Software
5.
Database (Oxford) ; 20242024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38958433

RESUMO

Myxobacteria are predatory bacteria with antimicrobial activity, utilizing complex mechanisms to kill their prey and assimilate their macromolecules. Having large genomes encoding hundreds of secondary metabolites, hydrolytic enzymes and antimicrobial peptides, these organisms are widely studied for their antibiotic potential. MyxoPortal is a comprehensive genomic database hosting 262 genomes of myxobacterial strains. Datasets included provide genome annotations with gene locations, functions, amino acids and nucleotide sequences, allowing analysis of evolutionary and taxonomical relationships between strains and genes. Biosynthetic gene clusters are identified by AntiSMASH, and dbAMP-generated antimicrobial peptide sequences are included as a resource for novel antimicrobial discoveries, while curated datasets of CRISPR/Cas genes, regulatory protein sequences, and phage associated genes give useful insights into each strain's biological properties. MyxoPortal is an intuitive open-source database that brings together application-oriented genomic features that can be used in taxonomy, evolution, predation and antimicrobial research. MyxoPortal can be accessed at http://dicsoft1.physics.iisc.ac.in/MyxoPortal/. Database URL:  http://dicsoft1.physics.iisc.ac.in/MyxoPortal/. Graphical Abstract.


Assuntos
Bases de Dados Genéticas , Genoma Bacteriano , Myxococcales , Myxococcales/genética , Genômica/métodos
6.
Pharm Biol ; 51(6): 728-36, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23577802

RESUMO

CONTEXT: Traditionally, many cultures use chewing sticks for oral hygiene maintenance. When properly used, these chewing sticks are found to be efficient due to the combined effect of mechanical cleaning, enhanced salivation and the antimicrobial action of leached out plant compounds. OBJECTIVE: Achyranthes aspera L. (Amaranthaceae), an ethanomedicinal herb was evaluated for its potential to inhibit growth and biofilm formation by cariogenic isolate Streptococcus mutans as an alternative means of caries management by quorum quenching (QQ). MATERIALS AND METHODS: Biofilm forming cariogenic isolates were isolated and their susceptibility to the petroleum ether, benzene, methanol, aqueous extracts of A. aspera was evaluated. Gas chromatography-mass spectrometry (GC-MS), phytochemical analyses and structure-based virtual screening for their quorum sensing (QS) inhibitory activities, drug-likeness and bioavailability were also carried out. RESULTS: The biofilm inhibition percentage obtained for methanol, benzene, petroleum ether and aqueous extracts (125 µg/mL) were ≤94%, ≤74%, ≤62% ≤42%, respectively. GC-MS analyses indicated 61 compounds, of which betulin recorded efficient interaction exhibiting comparable binding energy of -8.72 with S. mutans glycosyltransferase (GTF-SI) whereas 3,12-oleandione exhibited binding energy -5.92 with OmpR subfamily QS regulatory DNA-binding response regulator. Computer-assisted molecular descriptor and Lipinski's rule violation calculation uncovered the presence of more drug-like compounds. DISCUSSION AND CONCLUSION: Anticaries bioactive compounds of A. aspera with higher QS response regulator binding energy, low toxicity and optimal pharmacokinetic properties were revealed. These compounds with possible QQ ability hold the potential for use as anticaries drug leads and antibiofilm preventative medicine.


Assuntos
Achyranthes/química , Biofilmes/efeitos dos fármacos , Extratos Vegetais/farmacologia , Streptococcus mutans/efeitos dos fármacos , Simulação por Computador , Cárie Dentária/microbiologia , Cárie Dentária/prevenção & controle , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Medicina Tradicional , Extratos Vegetais/efeitos adversos , Extratos Vegetais/farmacocinética , Percepção de Quorum/efeitos dos fármacos , Solventes/química , Streptococcus mutans/isolamento & purificação , Streptococcus mutans/fisiologia
7.
Acta Crystallogr D Biol Crystallogr ; 68(Pt 1): 57-61, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22194333

RESUMO

The region spanning residues 95-146 of the rotavirus nonstructural protein NSP4 from the asymptomatic human strain ST3 has been purified and crystallized and diffraction data have been collected to a resolution of 2.6 Å. Several attempts to solve the structure by the molecular-replacement method using the available tetrameric structures of this domain were unsuccessful despite a sequence identity of 73% to the already known structures. A more systematic approach with a dimer as the search model led to an unexpected pentameric structure using the program Phaser. The various steps involved in arriving at this molecular-replacement solution, which unravelled a case of subtle variation between different oligomeric states unknown at the time of solving the structure, are presented in this paper.


Assuntos
Glicoproteínas/química , Estrutura Quaternária de Proteína , Rotavirus/química , Toxinas Biológicas/química , Proteínas não Estruturais Virais/química , Sequência de Aminoácidos , Cristalografia por Raios X , Modelos Moleculares , Dados de Sequência Molecular , Alinhamento de Sequência
8.
Acta Crystallogr F Struct Biol Commun ; 78(Pt 9): 338-346, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36048084

RESUMO

The crystal structure of an uncharacterized hypothetical protein, TTHA1873 from Thermus thermophilus, has been determined by X-ray crystallography to a resolution of 1.78 Šusing the single-wavelength anomalous dispersion method. The protein crystallized as a dimer in two space groups: P43212 and P6122. Structural analysis of the hypothetical protein revealed that the overall fold of TTHA1873 has a ß-sandwich jelly-roll topology with nine ß-strands. TTHA1873 is a dimeric metal-binding protein that binds to two Ca2+ ions per chain, with one on the surface and the other stabilizing the dimeric interface of the two chains. A structural homology search indicates that the protein has moderate structural similarity to one domain of cell-surface proteins or agglutinin receptor proteins. Red blood cells showed visible agglutination at high concentrations of the hypothetical protein.


Assuntos
Proteínas de Bactérias , Thermus thermophilus , Sequência de Aminoácidos , Proteínas de Bactérias/química , Sítios de Ligação , Cristalografia por Raios X , Thermus thermophilus/química
9.
Sci Rep ; 11(1): 16547, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34400660

RESUMO

Eco-restoration initiative work in the high altitude Dayara pastureland (3501 m) from the Indian Himalayan Region has been considered to be one of the successful field demonstration against both natural and anthropogenic degradation. The present study therefore attempts to assess the implications of entire eco-restoration model as practiced by Department of Forest, Government of Uttarakhand in 2019. Its assessment was done by calculating restoration success index by way of considering three categories, viz., direct management measure (M), environmental desirability (E) and socio-economic feasibility (SE) considering 22 individual variables. 'M' comprised both biotic and abiotic pressures. Grazing and tourism were biotic, while abiotic pressure was considered mainly soil erosion in alpine area due to topographic fragility. Above ground vegetation profile and below ground soil nutrient profile (N, P, K, pH and water holding capacity) were analyzed in 'E' component. In the last but not least, 'SE' was analyzed to assess the social acceptability of the local communities and stakeholders who are supposed to be ultimate beneficiary of alike interventions. Direct management measure was found with the variable index score of 0.8 indicating the higher score as compared to environmental desirability (0.56). Under direct management measure, grazing and tourists' carrying capacity of the area was analyzed with high management needs to call the region sustainable in terms of availability of bio-resources. The ecosystem index score was evaluated for the reference (81.94), treated (64.5) and untreated zones (52.03), wherein increasing profile of these values were found. The outcomes like improved vegetation profile in terms of total herb density, soil nutrient profile of the restored area along with soil pH (4.96) and water holding capacity (49.85%) were found to be restored significantly along with controlling 169.64 tonne year-1 soil erosion from draining. The assessment of grazing pattern of 118 migratory Cow Unit (CU) (76 horse/mule and 18 sheep/goat, already controlled), 318 local CU (30 horse/mule and 187 sheep/goat) were calculated and recommended to be controlled. Tourists' carrying capacity of 274 tourists per day and manual removal of Rumex nepalensis at the shepherd camping site were found to be worth to apply in the area. Use of biodegradable but locally sourced material and engaging local villagers in this endeavor were also found to be in harmony with SDG Goal 1 (no poverty). Therefore, the restoration and its evaluation model could have its future prospects to prove as a successful restoration practice. This restoration practice could not only be worth in high altitude degraded alpine pastures of the Indian Himalayan Region but also to other mountain alpine and sub-alpine ecosystems.

10.
Int J Tuberc Lung Dis ; 25(3): 182-190, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33688806

RESUMO

BACKGROUND: Approximately 10% of incident TB cases worldwide are attributable to alcohol. However, evidence associating alcohol with unfavorable TB treatment outcomes is weak.METHODS: We prospectively evaluated men (≥18 years) with pulmonary TB in India for up to 24 months to investigate the association between alcohol use and treatment outcomes. Unhealthy alcohol use was defined as a score of ≥4 on the Alcohol Use Disorders Identification Test-Concise (AUDIT-C) scale at entry. Unfavorable TB treatment outcomes included failure, recurrence, and all-cause mortality, analyzed as composite and independent endpoints.RESULTS: Among 751 men, we identified unhealthy alcohol use in 302 (40%). Median age was 39 years (IQR 28-50); 415 (55%) were underweight (defined as a body mass index [BMI] <18.5 kg/m²); and 198 (26%) experienced an unfavorable outcome. Unhealthy alcohol use was an independent risk factor for the composite unfavorable outcome (adjusted incidence rate ratio [aIRR] 1.47, 95% CI 1.05-2.06; P = 0.03) and death (aIRR 1.90, 95% CI 1.08-3.34; P = 0.03), specifically. We found significant interaction between AUDIT-C and BMI; underweight men with unhealthy alcohol use had increased risk of unfavorable outcomes (aIRR 2.22, 95% CI 1.44-3.44; P < 0.001) compared to men with BMI ≥18.5 kg/m² and AUDIT-C <4.CONCLUSION: Unhealthy alcohol use was independently associated with unfavorable TB treatment outcomes, highlighting the need for integrating effective alcohol interventions into TB care.


Assuntos
Alcoolismo , Tuberculose Pulmonar , Adulto , Consumo de Bebidas Alcoólicas/epidemiologia , Alcoolismo/epidemiologia , Humanos , Índia/epidemiologia , Masculino , Resultado do Tratamento
11.
J Mol Evol ; 70(5): 466-78, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20480157

RESUMO

The discovery of GH (Glycoside Hydrolase) 19 chitinases in Streptomyces sp. raises the possibility of the presence of these proteins in other bacterial species, since they were initially thought to be confined to higher plants. The present study mainly concentrates on the phylogenetic distribution and homology conservation in GH19 family chitinases. Extensive database searches are performed to identify the presence of GH19 family chitinases in the three major super kingdoms of life. Multiple sequence alignment of all the identified GH19 chitinase family members resulted in the identification of globally conserved residues. We further identified conserved sequence motifs across the major sub groups within the family. Estimation of evolutionary distance between the various bacterial and plant chitinases are carried out to better understand the pattern of evolution. Our study also supports the horizontal gene transfer theory, which states that GH19 chitinase genes are transferred from higher plants to bacteria. Further, the present study sheds light on the phylogenetic distribution and identifies unique sequence signatures that define GH19 chitinase family of proteins. The identified motifs could be used as markers to delineate uncharacterized GH19 family chitinases. The estimation of evolutionary distance between chitinase identified in plants and bacteria shows that the flowering plants are more related to chitinase in actinobacteria than that of identified in purple bacteria. We propose a model to elucidate the natural history of GH19 family chitinases.


Assuntos
Proteínas de Bactérias/genética , Quitinases/genética , Evolução Molecular , Proteínas de Plantas/genética , Actinobacteria/genética , Motivos de Aminoácidos , Bases de Dados Genéticas , Modelos Moleculares , Filogenia , Plantas/genética , Proteobactérias/genética , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos
12.
Proteins ; 77(4): 760-77, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19544573

RESUMO

Molecular dynamics simulations have been carried out on all the jacalin-carbohydrate complexes of known structure, models of unliganded molecules derived from the complexes and also models of relevant complexes where X-ray structures are not available. Results of the simulations and the available crystal structures involving jacalin permit delineation of the relatively rigid and flexible regions of the molecule and the dynamical variability of the hydrogen bonds involved in stabilizing the structure. Local flexibility appears to be related to solvent accessibility. Hydrogen bonds involving side chains and water bridges involving buried water molecules appear to be important in the stabilization of loop structures. The lectin-carbohydrate interactions observed in crystal structures, the average parameters pertaining to them derived from simulations, energetic contribution of the stacking residue estimated from quantum mechanical calculations, and the scatter of the locations of carbohydrate and carbohydrate-binding residues are consistent with the known thermodynamic parameters of jacalin-carbohydrate interactions. The simulations, along with X-ray results, provide a fuller picture of carbohydrate binding by jacalin than provided by crystallographic analysis alone. The simulations confirm that in the unliganded structures water molecules tend to occupy the positions occupied by carbohydrate oxygens in the lectin-carbohydrate complexes. Population distributions in simulations of the free lectin, the ligands, and the complexes indicate a combination of conformational selection and induced fit.


Assuntos
Lectinas de Plantas/química , Sítios de Ligação , Carboidratos/química , Sequência Conservada , Cristalografia por Raios X , Ligação de Hidrogênio , Modelos Moleculares , Estrutura Molecular , Complexos Multiproteicos/química , Lectinas de Plantas/genética , Estrutura Quaternária de Proteína , Subunidades Proteicas , Termodinâmica , Água/química
13.
J Biosci ; 34(1): 103-12, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19430122

RESUMO

Amino acid sequences are known to constantly mutate and diverge unless there is a limiting condition that makes such a change deleterious. However, closer examination of the sequence and structure reveals that a few large, cryptic repeats are nevertheless sequentially conserved. This leads to the question of why only certain repeats are conserved at the sequence level. It would be interesting to find out if these sequences maintain their conservation at the three-dimensional structure level. They can play an active role in protein and nucleotide stability, thus not only ensuring proper functioning but also potentiating malfunction and disease. Therefore,insights into any aspect of the repeats - be it structure, function or evolution - would prove to be of some importance. This study aims to address the relationship between protein sequence and its three-dimensional structure, by examining if large cryptic sequence repeats have the same structure.


Assuntos
Evolução Molecular , Sequências Repetitivas de Aminoácidos , Sequência de Aminoácidos , Análise por Conglomerados , Simulação por Computador , Sequência Conservada , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Terciária de Proteína
14.
J Biosci ; 34(1): 27-34, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19430116

RESUMO

The role of invariant water molecules in the activity of plant cysteine protease is ubiquitous in nature. On analysing the 11 different Protein DataBank (PDB) structures of plant thiol proteases, the two invariant water molecules W1 and W2 (W220 and W222 in the template 1PPN structure) were observed to form H-bonds with the O b atom of Asn 175. Extensive energy minimization and molecular dynamics simulation studies up to 2 ns on all the PDB and solvated structures clearly revealed the involvement of the H-bonding association of the two water molecules in fixing the orientation of the asparagine residue of the catalytic triad. From this study,it is suggested that H-bonding of the water molecule at the W1 invariant site better stabilizes the Asn residue at the active site of the catalytic triad.


Assuntos
Asparagina/química , Cisteína Endopeptidases/química , Proteínas de Plantas/química , Água/química , Catálise , Simulação por Computador , Cristalografia por Raios X , Ligação de Hidrogênio , Cinética , Modelos Moleculares , Oxigênio/química , Plantas/enzimologia , Estrutura Terciária de Proteína
15.
Int J Biol Macromol ; 136: 368-376, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31207327

RESUMO

Misfolding of the cellular prion protein (PrPC) into ß-sheet-rich scrapie form (PrPSc) is associated with transmissible spongiform encephalopathies. A point mutation F198S is responsible for the development of a rare inherited Gerstmann-Straussler-Scheinker disease caused by the aggregation of PrPC. Thus, identification and the structural characterization of aggregation-prone regions are essential to delineate the conversion of PrPC to the disease-associated PrPSc upon F198S mutation. In the present study, molecular dynamics simulations on the wild-type PrP (WT-PrP) and its mutant were performed to explore the structural basis responsible for aggregation driven by the mutation. Secondary structure analysis revealed that the mutant exhibited a partial unfolding on α2 and the complete distortion in the 310-helix of the ß2-α2 loop. Remarkably, the ß2-α2 loop is in proximity to α3 attributed by the long-range hydrophobic interactions and such structural intimacy is not observed in the WT-PrP. Owing to this, the ß1-α1-ß2 regions have separated from α2-α3 domain resulting in the impairment on the hydrogen bond between α1 and α3. Thus, the present study provides a detailed structural description of the F198S mutant in line with previous experimental results and delivers insights into the structural basis responsible for the conversion of PrPC to the disease-associated PrPSc.


Assuntos
Simulação de Dinâmica Molecular , Proteínas PrPC/química , Proteínas PrPSc/química , Proteínas Priônicas/química , Ligação de Hidrogênio , Mutação , Proteínas Priônicas/genética , Conformação Proteica em alfa-Hélice , Domínios Proteicos , Redobramento de Proteína , Termodinâmica
16.
Comput Biol Chem ; 78: 424-430, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30598392

RESUMO

Evolution builds up new genetic material from existing ones, not in random, but in highly ordered and eloquent patterns. Most of these sequence repeats are revelatory of valuable information contributing to areas of disease research and function of macromolecules, to name a few. In the age of next generation genome sequencing, rapid and efficient extraction of all unbiased sequence repeats from macromolecules is the need of the hour. In view of this reckoning, an online web-based computing server, RepEx, has been developed to extract and display all possible repeats for DNA and protein sequences. Apart from exact or identical repeats, the server has been designed adeptly to identify and extract degenerate, inverted, everted and mirror repeats from both DNA and protein sequences. The server has striking output displays, featuring interactive graphs and comprehensive output files. In addition, RepEx has been accoutered with an easy-to-use interface and search filters to facilitate a user-defined query or search and is freely available and accessible via the World Wide Web at http://bioserver2.physics.iisc.ac.in/RepEx/.


Assuntos
DNA/genética , Internet , Repetições de Microssatélites/genética , Proteínas/genética , Software , Interface Usuário-Computador , Sequência de Aminoácidos
17.
J Mol Biol ; 370(4): 752-67, 2007 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-17543333

RESUMO

Mycobacterium smegmatis Dps degrades spontaneously into a species in which 16 C-terminal residues are cleaved away. A second species, in which all 26 residues constituting the tail were deleted, was cloned, expressed and purified. The first did not bind DNA but formed dodecamers like the native protein, while the second did not bind to DNA and failed to assemble into dodecamers, indicating a role in assembly also for the tail. In the crystal structure of the species without the entire C-terminal tail the molecule has an unusual open decameric structure resulting from the removal of two adjacent subunits from the original dodecameric structure of the native form. A Dps dodecamer could assemble with a dimer or one of two trimers (trimer-A and trimer-B) as intermediate. Trimer-A is the intermediate species in the M. smegmatis protein. Estimation of the surface area buried on trimerization indicates that association within trimer-B is weak. It weakens further when the C-terminal tail is removed, leading to the disruption of the dodecameric structure. Thus, the C-terminal tail has a dual role, one in DNA binding and the other in the assembly of the dodecamer. M. smegmatis Dps also has a short N-terminal tail. A species with nine N-terminal residues deleted formed trimers but not dodecamers in solution, unlike wild-type M. smegmatis Dps, under the same conditions. Unlike in solution, the N-terminal mutant forms dodecamers in the crystal. In native Dps, the N-terminal stretch of one subunit and the C-terminal stretch of a neighboring subunit lock each other into ordered positions. The deletion of one stretch results in the disorder of the other. This disorder appears to result in the formation of a trimeric species of the N-terminal deletion mutant contrary to the indication provided by the native structure. The ferroxidation site is intact in the mutants.


Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , DNA/metabolismo , Proteínas Mutantes/metabolismo , Mycobacterium smegmatis/química , Mycobacterium smegmatis/genética , Deleção de Sequência/genética , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Sequência Conservada , Cristalografia por Raios X , Proteínas de Ligação a DNA/genética , Modelos Moleculares , Dados de Sequência Molecular , Proteínas Mutantes/química , Proteínas Mutantes/genética , Dobramento de Proteína , Estrutura Quaternária de Proteína , Estrutura Terciária de Proteína , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Alinhamento de Sequência
18.
J Perinatol ; 28 Suppl 1: S60-2, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18446180

RESUMO

Persistent patent ductus arteriosus (PDA) in preterm infants can result in serious hemodynamic changes causing respiratory, gastrointestinal and renal morbidities if not treated within the first week of life. The treatment options available are a conservative approach, pharmacological treatment with cyclo-oxygenase (COX) inhibitors and surgical ligation. The COX inhibitors approved for use in the United States are indomethacin and ibuprofen lysine. Both of these drugs are equally effective in closing the PDA. Subtle differences exist between these two preparations. Indomethacin has a protective effect on the incidence of intraventricular hemorrhage (IVH) but reduces the blood flow to the kidneys and the brain. Ibuprofen is less toxic but has no effect on IVH. Efficacy of pharmacological treatment is influenced by timing of initiation of therapy. Surgical treatment is the only option when pharmacological treatment fails to close the PDA in symptomatic infants. Long-term neurological and respiratory morbidities are associated with surgical ligation. This paper reviews these medical considerations in the treatment options for PDA in premature infants.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Inibidores de Ciclo-Oxigenase/uso terapêutico , Permeabilidade do Canal Arterial/tratamento farmacológico , Ibuprofeno/análogos & derivados , Indometacina/uso terapêutico , Lisina/análogos & derivados , Anti-Inflamatórios não Esteroides/efeitos adversos , Inibidores de Ciclo-Oxigenase/efeitos adversos , Permeabilidade do Canal Arterial/diagnóstico , Humanos , Ibuprofeno/efeitos adversos , Ibuprofeno/uso terapêutico , Indometacina/efeitos adversos , Recém-Nascido , Lisina/efeitos adversos , Lisina/uso terapêutico
19.
Nucleic Acids Res ; 34(Web Server issue): W128-32, 2006 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-16844975

RESUMO

3dSS is a web-based interactive computing server, primarily designed to aid researchers, to superpose two or several 3D protein structures. In addition, the server can be effectively used to find the invariant and common water molecules present in the superposed homologous protein structures. The molecular visualization tool RASMOL is interfaced with the server to visualize the superposed 3D structures with the water molecules (invariant or common) in the client machine. Furthermore, an option is provided to save the superposed 3D atomic coordinates in the client machine. To perform the above, users need to enter Protein Data Bank (PDB)-id(s) or upload the atomic coordinates in PDB format. This server uses a locally maintained PDB anonymous FTP server that is being updated weekly. This program can be accessed through our Bioinformatics web server at the URL http://cluster.physics.iisc.ernet.in/3dss/ or http://10.188.1.15/3dss/.


Assuntos
Software , Homologia Estrutural de Proteína , Gráficos por Computador , Bases de Dados de Proteínas , Internet , Modelos Moleculares , Fosfolipases A/química , Água/química
20.
Int J Biol Macromol ; 43(4): 333-8, 2008 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-18674557

RESUMO

A comparative study of water molecules and ion pairs in 11 Dps protein structures has been carried out. The invariant and common water molecules, the conserved residues interacting with them and the conserved ion pairs have been analyzed. Certain water molecules found on the interfaces between subunits are highly conserved and may be implicated in flexibility or continuing association of the subunits of the structure. It is possible that the water molecules, ion pairs and the special case of a water mediated charged network through a single water molecule are involved in maintaining the stability of the protein.


Assuntos
Ferritinas/química , Proteínas/química , Água/química , Íons , Estrutura Secundária de Proteína , Subunidades Proteicas/química
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