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1.
Circ J ; 2024 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-39401917

RESUMO

BACKGROUND: The optimal duration of dual antiplatelet therapy (DAPT) in patients with chronic kidney disease undergoing percutaneous coronary intervention (PCI), especially with third-generation drug-eluting stents (DES), remains unknown. METHODS AND RESULTS: We conducted a prespecified post hoc analysis of the HOST-IDEA trial, randomizing patients undergoing PCI with third-generation DES to 3- to 6-month or 12-month DAPT. In all, 1,997 patients were grouped by their estimated glomerular filtration rate (eGFR): high (>90 mL/min/1.73 m2), intermediate (60-90 mL/min/1.73 m2), and low (<60 mL/min/1.73 m2). The primary outcome was net adverse clinical events (NACE), a composite of cardiac death, target vessel myocardial infarction, clinically driven target lesion revascularization, stent thrombosis, or major bleeding (Bleeding Academic Research Consortium Type 3 or 5) at 12 months. Secondary outcomes were target lesion failure (TLF) and major bleeding. The low eGFR group had the highest rates of NACE, TLF, and major bleeding compared with the other 2 groups (P<0.001). Rates of NACE were similar in the 3- to 6-month and 12-month DAPT in the high (2.9% vs. 3.2%; P=0.84), intermediate (2.1% vs. 2.8%, P=0.51), and low (8.9% vs. 9.1%; hazard ratio 0.99; P=0.97; Pinteraction=0.88) eGFR groups. TLF and major bleeding events showed similar trends. CONCLUSIONS: In patients undergoing PCI with third-generation DES, 3- to 6-month DAPT was comparable to 12-month DAPT for clinical outcomes regardless of renal function.

2.
Trends Biochem Sci ; 43(10): 790-805, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30139647

RESUMO

Polyhydroxyalkanoates (PHAs) are diverse biopolyesters produced by numerous microorganisms and have attracted much attention as a substitute for petroleum-based polymers. Despite several decades of study, the detailed molecular mechanisms of PHA biosynthesis have remained unknown due to the lack of structural information on the key PHA biosynthetic enzyme PHA synthase. The recently determined crystal structure of PHA synthase, together with the structures of acetyl-coenzyme A (CoA) acetyltransferase and reductase, have changed this situation. Structural and biochemical studies provided important clues for the molecular mechanisms of each enzyme as well as the overall mechanism of PHA biosynthesis from acetyl-CoA. This new information and knowledge is expected to facilitate production of designed novel PHAs and also enhanced production of PHAs.


Assuntos
Poli-Hidroxialcanoatos/metabolismo , Acetato-CoA Ligase/metabolismo , Acetil-CoA C-Acetiltransferase/metabolismo , Oxirredutases do Álcool/metabolismo , Catálise , Estrutura Molecular , Poli-Hidroxialcanoatos/química , Polimerização , Especificidade por Substrato
3.
Cardiovasc Diabetol ; 21(1): 82, 2022 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-35606846

RESUMO

BACKGROUND: Statin treatment increases the risk of new-onset diabetes mellitus (NODM); however, data directly comparing the risk of NODM among individual statins is limited. We compared the risk of NODM between patients using pitavastatin and atorvastatin or rosuvastatin using reliable, large-scale data. METHODS: Data of electronic health records from ten hospitals converted to the Observational Medical Outcomes Partnership Common Data Model (n = 14,605,368 patients) were used to identify new users of pitavastatin, atorvastatin, or rosuvastatin (atorvastatin + rosuvastatin) for ≥ 180 days without a previous history of diabetes or HbA1c level ≥ 5.7%. We conducted a cohort study using Cox regression analysis to examine the hazard ratio (HR) of NODM after propensity score matching (PSM) and then performed an aggregate meta-analysis of the HR. RESULTS: After 1:2 PSM, 10,238 new pitavastatin users (15,998 person-years of follow-up) and 18,605 atorvastatin + rosuvastatin users (33,477 person-years of follow-up) were pooled from 10 databases. The meta-analysis of the HRs demonstrated that pitavastatin resulted in a significantly reduced risk of NODM than atorvastatin + rosuvastatin (HR 0.72; 95% CI 0.59-0.87). In sub-analysis, pitavastatin was associated with a lower risk of NODM than atorvastatin or rosuvastatin after 1:1 PSM (HR 0.69; CI 0.54-0.88 and HR 0.74; CI 0.55-0.99, respectively). A consistently low risk of NODM in pitavastatin users was observed when compared with low-to-moderate-intensity atorvastatin + rosuvastatin users (HR 0.78; CI 0.62-0.98). CONCLUSIONS: In this retrospective, multicenter active-comparator, new-user, cohort study, pitavastatin reduced the risk of NODM compared with atorvastatin or rosuvastatin.


Assuntos
Diabetes Mellitus , Inibidores de Hidroximetilglutaril-CoA Redutases , Atorvastatina/efeitos adversos , Estudos de Coortes , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/tratamento farmacológico , Diabetes Mellitus/epidemiologia , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Estudos Multicêntricos como Assunto , Quinolinas , Estudos Retrospectivos , Rosuvastatina Cálcica/efeitos adversos
4.
Arch Biochem Biophys ; 730: 109391, 2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36087768

RESUMO

Cupriavidus necator H16 is a gram-negative chemolithoautotrophic bacterium that has been extensively studied for biosynthesis and biodegradation of polyhydroxyalkanoate (PHA) plastics. To improve our understanding of fatty acid metabolism for PHA production, we determined the crystal structure of multi-functional enoyl-CoA hydratase from Cupriavidus necator H16 (CnFadB). The predicted model of CnFadB created by AlphaFold was used to solve the phase problem during determination of the crystal structure of the protein. The CnFadB structure consists of two distinctive domains, an N-terminal enol-CoA hydratase (ECH) domain and a C-terminal 3-hydroxyacyl-CoA dehydrogenase (HAD) domain, and the substrate- and cofactor-binding modes of these two functional domains were identified. Unlike other known FadB enzymes that exist as dimers complexed with FadA, CnFadB functions as a monomer without forming a complex with CnFadA. Small angle X-ray scattering (SAXS) measurement further proved that CnFadB exists as a monomer in solution. The non-sequential action of FadA and FadB in C. necator appears to affect ß-oxidation and PHA synthesis/degradation.


Assuntos
Cupriavidus necator , Poli-Hidroxialcanoatos , Cupriavidus necator/metabolismo , Poli-Hidroxialcanoatos/metabolismo , Espalhamento a Baixo Ângulo , Difração de Raios X , Enoil-CoA Hidratase/metabolismo , Ácidos Graxos/metabolismo , Plásticos/metabolismo , 3-Hidroxiacil-CoA Desidrogenase/metabolismo , Coenzima A/metabolismo
5.
Biochem Biophys Res Commun ; 583: 43-48, 2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34735878

RESUMO

The coding gene for peptidoglycan editing factor (pdeF) is located in the division and cell wall (dcw) cluster, and encodes a protein that has an editing function for misplaced amino acids in peptidoglycan in E. coli. In this study, we determined the crystal structure of PdeF from Bacillus cereus (BcPdeF) at a 1.60 Å resolution. BcPdeF exists as a monomer in solution and consists of two domains: a core domain containing a Pfam motif DUF152 and a smaller subdomain. The X-ray fluorescence spectrum of BcPdeF crystal elucidated that the protein has a Zn2+ ion in its active site and the metal ion was coordinated by two histidine and one cysteine residue. We also performed docking calculations of the N-acetylmuramate (MurNAc)-L-Ser-D-iGlu ligand in the BcPdeF structure and revealed the substrate binding mode of the enzyme. Furthermore, structural comparisons between BcPdeF and human fatty acid metabolism-immunity nexus (FAMIN), which also contains the DUF152 motif in its core domain, provided a structural basis how the two structurally similar proteins have completely different physiological functions.

6.
Environ Microbiol ; 22(1): 270-285, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31657110

RESUMO

Fumarylacetoacetate hydrolase (FAH) superfamily proteins are found ubiquitously in microbial pathways involved in the catabolism of aromatic substances. Although extensive bioinformatic data on these proteins have been acquired, confusion caused by problems with the annotation of these proteins hinders research into determining their physiological functions. Here we classify 606 FAH superfamily proteins using a maximum likelihood (ML) phylogenetic tree, comparative gene-neighbourhood patterns and in vitro enzyme assays. The FAH superfamily proteins used for the analyses are divided into five distinct subfamilies, and two of them, FPH-A and FPH-B, contain the majority of the proteins of undefined function. These subfamilies include clusters designated FPH-I and FPH-II, respectively, which include two distinct types of fumarylpyruvate hydrolase (FPH), an enzyme involved in the final step of the gentisate pathway. We determined the crystal structures of these FPH enzymes at 2.0 Å resolutions and investigate the substrate binding mode by which these types of enzymes can accommodate fumarylpyruvate as a substrate. Consequentially, we identify the molecular signatures of the two types of FPH enzymes among the broadly conserved FAH superfamily proteins. Our studies allowed us to predict the relationship of unknown FAH superfamily proteins using their sequence information.


Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/classificação , Hidrolases/química , Hidrolases/classificação , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Hidrolases/genética , Hidrolases/metabolismo , Filogenia
7.
Environ Microbiol ; 22(2): 752-765, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31814251

RESUMO

The bi-functional malonyl-CoA reductase is a key enzyme of the 3-hydroxypropionate bi-cycle for bacterial CO2 fixation, catalysing the reduction of malonyl-CoA to malonate semialdehyde and further reduction to 3-hydroxypropionate. Here, we report the crystal structure and the full-length architecture of malonyl-CoA reductase from Porphyrobacter dokdonensis. The malonyl-CoA reductase monomer of 1230 amino acids consists of four tandemly arranged short-chain dehydrogenases/reductases, with two catalytic and two non-catalytic short-chain dehydrogenases/reductases, and forms a homodimer through paring contact of two malonyl-CoA reductase monomers. The complex structures with its cofactors and substrates revealed that the malonyl-CoA substrate site is formed by the cooperation of two short-chain dehydrogenases/reductases and one novel extra domain, while only one catalytic short-chain dehydrogenase/reductase contributes to the formation of the malonic semialdehyde-binding site. The phylogenetic and structural analyses also suggest that the bacterial bi-functional malonyl-CoA has a structural origin that is completely different from the archaeal mono-functional malonyl-CoA and malonic semialdehyde reductase, and thereby constitute an efficient enzyme.


Assuntos
Alphaproteobacteria/enzimologia , Malondialdeído/análogos & derivados , Malonil Coenzima A/metabolismo , Oxirredutases/metabolismo , Sítios de Ligação/fisiologia , Ácido Láctico/análogos & derivados , Ácido Láctico/metabolismo , Malondialdeído/metabolismo , Filogenia , Ligação Proteica/fisiologia , Conformação Proteica
8.
Biochem Biophys Res Commun ; 533(3): 442-448, 2020 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-32972748

RESUMO

Bacillus cereus ATCC 14579 is a known polyhydroxybutyrate (PHB)-producing microorganism that possesses genes associated with PHB synthesis such as PhaA, PhaB, and PHA synthases. PhaA (i.e., thiolase) is the first enzyme in the PHA biosynthetic pathway, which catalyze the condensation of two acetyl-CoA molecules to acetoacetyl-CoA. Our study elucidated the crystal structure of PhaA in Bacillus cereus ATCC 14579 (BcTHL) in its apo- and CoA-bound forms. BcTHL adopts a type II biosynthetic thiolase structure by forming a tetramer. The crystal structure of CoA-complexed BcTHL revealed that the substrate binding site of BcTHL is constituted by different residues compared with other known thiolases. Our study also revealed that Arg221, a residue involved in ADP binding, undergoes a positional conformational change upon the binding of the CoA molecule.


Assuntos
Acetil-CoA C-Acetiltransferase/química , Bacillus cereus/enzimologia , Proteínas de Bactérias/química , Domínio Catalítico , Coenzima A/química , Cristalografia por Raios X , Hidroxibutiratos/metabolismo , Modelos Moleculares
9.
Biochem Biophys Res Commun ; 533(4): 824-830, 2020 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-32993959

RESUMO

Glycine oxidase (GO) is an enzyme that catalyzes the oxidation of the primary and secondary amines of various chemicals, including glycine, and the enzyme has been applied in a variety of fields, such as biosensor and genetically modified glyphosate resistance plants. Here, we report that the gene product of BC0747 from Bacillus cereus (BcGO) shows oxidase activity for glycine and small d-amino acids, such as d-proline and d-alanine. We also determined the crystal structure of BcGO complexed with the FAD cofactor at a 2.36 Å resolution and revealed how the cofactor binds to the deep pocket of the enzyme. We performed the molecular docking calculation of the glycine substrate to the BcGO structure and identified how the carboxyl- and amine-groups of the d-amino acid are stabilized at the substrate binding site. Structural analysis of BcGO also provided information on the structural basis for the stereospecificity of the enzyme to d-amino acids. In addition, we placed the glyphosate molecule, a plant herbicide, at the substrate binding site, and explained how the mutation of Gly51 to arginine enhances enzyme activity.


Assuntos
Aminoácido Oxirredutases/química , Aminoácidos/química , Bacillus cereus/enzimologia , Aminoácido Oxirredutases/metabolismo , Aminoácidos/metabolismo , Domínio Catalítico , Flavina-Adenina Dinucleotídeo/química , Glicina/análogos & derivados , Glicina/química , Glicina/metabolismo , Cinética , Modelos Moleculares , Ligação Proteica , Estereoisomerismo , Glifosato
10.
Biochem Biophys Res Commun ; 528(3): 426-431, 2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32505353

RESUMO

Methylobacterium extorquens is a methylotroph model organism that has the ability to assimilate formate using the tetrahydrofolate (THF) pathway. The formate-tetrahydrofolate ligase from M. extorquens (MeFtfL) is an enzyme involved in the THF pathway that catalyzes the conversion of formate, THF, and ATP into formyltetrahydrofolate and ADP. To investigate the biochemical properties of MeFtfL, we evaluated the metal usage and enzyme kinetics of the enzyme. MeFtfL uses the Mg ion for catalytic activity, but also has activity for Mn and Ca ions. The enzyme kinetics analysis revealed that Km value of farmate was much higher than THF and ATP, which shows that the ligation activity of MeFtfL is highly dependent on formation concentration. We also determined the crystal structure of MeFtfL at 2.8 Å resolution. MeFtfL functions as a tetramer, and each monomer consists of three domains. The structural superposition of MeFtfL with FtfL from Moorella thermoacetica allowed us to predict the substrate binding site of the enzyme.


Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Formiato-Tetra-Hidrofolato Ligase/química , Formiato-Tetra-Hidrofolato Ligase/metabolismo , Methylobacterium extorquens/enzimologia , Proteínas de Bactérias/genética , Domínio Catalítico , Cristalografia por Raios X , Formiato-Tetra-Hidrofolato Ligase/genética , Formiatos/metabolismo , Cinética , Redes e Vias Metabólicas , Methylobacterium extorquens/genética , Modelos Moleculares , Domínios e Motivos de Interação entre Proteínas , Estrutura Quaternária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
11.
Biochem Biophys Res Commun ; 533(4): 1177-1183, 2020 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-33041004

RESUMO

The glyoxylate cycle is an important anabolic pathway and acts under a C2 compound (such as acetic acid) rich condition in bacteria. The isocitrate lyase (ICL) enzyme catalyzes the first step in the glyoxylate cycle, which is the cleavage of isocitrate to glyoxylate and succinate. This enzyme is a metalo-enzyme that contains an Mg2+ or a Mn2+ion at the active site for enzyme catalysis. We expressed and purified ICL from Bacillus cereus (BcICL) and investigated its biochemical properties and metal usage through its enzyme activity and stability with various divalent metal ion. Based on the results, BcICL mainly utilized the Mg2+ ion for enzyme catalysis as well as the Mn2+, Ni2+ and Co2+ ions. To elucidate its molecular mechanisms, we determined the crystal structure of BcICL at 1.79 Å. Through this structure, we analyzed a tetrameric interaction of the protein. We also determined the BcICL structure in complex with both the metal and its products, glyoxylate and succinate at 2.50 Å resolution and revealed each ligand binding modes.


Assuntos
Bacillus cereus/enzimologia , Isocitrato Liase/química , Domínio Catalítico , Cristalografia por Raios X , Glioxilatos/química , Isocitrato Liase/metabolismo , Magnésio/química , Metais/química , Modelos Moleculares , Multimerização Proteica , Alinhamento de Sequência , Análise de Sequência de Proteína , Ácido Succínico/química
12.
Opt Express ; 28(24): 35972-35985, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33379702

RESUMO

In this paper, we propose a new system for a real-time holographic augmented reality (AR) video service based on a photorealistic three-dimensional (3D) object point for multiple users to use simultaneously at various locations and viewpoints. To observe the object from all viewpoints, a camera system capable of acquiring the 3D volume of a real object is developed and is used to generate a real object in real-time. Using the normal of the object point, the observable points are mapped to the viewpoint at which the user is located, and a hologram based on the object point is generated. The angle at which the reflected light from each point is incident on the hologram plane is calculated, and the intensity of the interference light is adjusted according to the angle to generate a hologram with a higher 3D effect. The generated hologram is transmitted to each user to provide a holographic AR service. The entire system consists of a camera system comprising eight RGB-D (depth) cameras and two workstations for photorealistic 3D volume and hologram generation. Using this technique, a realistic hologram was generated. Through experiments displaying holograms simultaneously from several different viewpoints, it is confirmed that multiple users can concurrently receive hologram AR.

13.
Opt Express ; 28(24): 36327-36345, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33379729

RESUMO

In this paper, we propose a new method for coding a full complex hologram with random phase. Since holograms with random phase have very unique spatial and frequency characteristics, a new compression method suitable for such holograms is required. We analyze the frequency characteristics of holograms with random phases and propose a new adaptive discrete wavelet transform (aDWT). Next, we propose a new modified zerotree alogrithm (mZTA) suitable for the subband configuration generated by the modified wavelet transform method. The results of the compression using the proposed method showed higher efficiency than the previous method, and the reconstructed images showed visually superior results.

14.
Biochem Biophys Res Commun ; 514(3): 601-606, 2019 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-31072617

RESUMO

γ-Aminobutyrate (GABA), a four carbon non-protein amino acid, is used by some microorganisms as a source of carbon and/or nitrogen. Corynebacterium glutamicum has an incomplete GABA shunt that lacks a glutamate decarboxylase coding gene for the conversion of glutamate to GABA. Recently, a novel GABA assimilation system was identified in C. glutamicum. In the cell, GABA aminotransferase (GABA-AT) is the first step of GABA assimilation in the process of utilizing GABA as a carbon and/or nitrogen source. In this study, we report the crystal structure of CgGABA-AT in complex with PLP-GABA. We used structural studies and site-directed mutagenesis experiments to identify the key residues that contribute to the formation of the active site. Furthermore, based on structural comparisons and amino acid sequence alignment, we demonstrate the differences between the GABA-ATs of bacteria, fungi, and animals.


Assuntos
4-Aminobutirato Transaminase/química , 4-Aminobutirato Transaminase/metabolismo , Corynebacterium glutamicum/enzimologia , Fosfato de Piridoxal/metabolismo , Ácido gama-Aminobutírico/metabolismo , Sequência de Aminoácidos , Domínio Catalítico , Cristalografia por Raios X , Modelos Moleculares , Homologia Estrutural de Proteína
15.
Biochem Biophys Res Commun ; 514(3): 991-997, 2019 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-31092332

RESUMO

Pseudomonas aeruginosa PAO1 can utilize various aromatic hydrocarbons as a carbon source. Among the three genes involved in the gentisate pathway of P. aeruginosa, the gene product of PA2473 belongs to the ζ-class glutathione S-transferase and is predicted to be a maleylpyruvate isomerase. In this study, we determined the crystal structure of maleylpyruvate isomerase from Pseudomonas aeruginosa PAO1 (PaMPI) at a resolution of 1.8 Å. PaMPI functions as a dimer and shows the glutathione S-transferase fold. The structure comparison with other glutathione S-transferase structures enabled us to predict the glutathione cofactor binding site and suggests that PaMPI has differences in residues that make up the putative substrate binding site. Biochemical study of PaMPI showed that the protein has an MPI activity. Interestingly, unlike the reported glutathione S-transferases so far, the purified PaMPI showed isomerase activity without the addition of the reduced glutathione, although the protein showed much higher activity when the glutathione cofactor was added to the reaction mixture. Taken together, our studies reveal that the gene product of PA2473 functions as a maleylpyruvate isomerase and might be involved in the gentisate pathway.


Assuntos
Pseudomonas aeruginosa/enzimologia , cis-trans-Isomerases/química , Sítios de Ligação , Cristalografia por Raios X , Gentisatos/metabolismo , Glutationa/metabolismo , Humanos , Modelos Moleculares , Conformação Proteica , Multimerização Proteica , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/química , Pseudomonas aeruginosa/metabolismo , Especificidade por Substrato , cis-trans-Isomerases/metabolismo
16.
Biochem Biophys Res Commun ; 514(3): 765-771, 2019 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-31079929

RESUMO

Sphingobium sp. strain SYK-6, an aerobic gram-negative bacillus found in soil, is known for utilizing lignin-derived monoaryls and biaryls as carbon sources and degrading aromatic compounds. The Sphingobium sp. strain SYK-6 genome contains three genes involved in salicylate catabolism: SLG_11260, SLG_11270, and SLG_11280. Here, we report that the gene product of SLG_11280 functions as a maleylpyruvate hydrolase (SsMPH) with Km and Kcat values of 166.2 µM and 3.76 min-1, respectively. This study also reveals the crystal structures of both the apo and pyruvate-manganese ion-bound SsMPH, which revealed that like other fumarylacetoacetate hydrolases, SsMPH dimerizes and has nine unique 310-helices. Molecular docking studies of maleylpyruvate also revealed the likely binding mode of SsMPH and its substrate.


Assuntos
Hidrolases/química , Hidrolases/metabolismo , Lignina/metabolismo , Sphingomonadaceae/enzimologia , Sequência de Aminoácidos , Domínio Catalítico , Modelos Moleculares , Ácido Salicílico/metabolismo , Especificidade por Substrato
17.
Biochem Biophys Res Commun ; 509(3): 833-838, 2019 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-30638660

RESUMO

Metallosphaera sedula is a thermoacidophilic autotrophic archaeon and known to utilize the 3-hydroxypropionate/4-hydroxybutyrate cycle (3-HP/4-HB cycle) as a carbon fixation pathway. The 3-HP/4-HB cycle in M. sedula is associated with central metabolism, and malate dehydrogenase (MDH) is an enzyme involved in the central metabolism that converts malate to oxaloacetate. To elucidate the enzymatic properties of MDH from M. sedula (MsMDH), we determined the crystal structure of MsMDH as a complex with NAD+ and a ternary complex with malate and NAD+. Based on its complex structures and biochemical experiments, we observed that MsMDH can utilize both NAD+ and NADP+ as a cofactor. In addition, we revealed that MsMDH shows a conformational change at the active site upon substrate binding. Based on the comparison with other MDHs, we revealed that MsMDH was distinguished from general MDHs due to a Lys80 residue, and this difference is likely to influence the unique cofactor specificity of MsMDH.


Assuntos
Proteínas Arqueais/química , Malato Desidrogenase/química , Sulfolobaceae/química , Proteínas Arqueais/metabolismo , Domínio Catalítico , Cristalografia por Raios X , Malato Desidrogenase/metabolismo , Malatos/metabolismo , Modelos Moleculares , Conformação Proteica , Especificidade por Substrato , Sulfolobaceae/enzimologia , Sulfolobaceae/metabolismo
18.
Biochem Biophys Res Commun ; 509(3): 722-727, 2019 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-30611567

RESUMO

Metallosphaera sedula is a thermoacidophilic archaeon that has carbon fixation ability using the 3-hydroxypropionate/4-hydroxybutyrate(3-HP/4-HB) cycle, and has an incomplete TCA cycle to produce necessary biosynthetic precursors. The citrate synthase from M. sedula (MsCS) is an enzyme involved in the first step of the incomplete TCA cycle, catalyzing the conversion of oxaloacetate and acetyl-CoA into citrate and coenzyme A. To investigate the molecular mechanism of MsCS, we determined its crystal structure at 1.8 Šresolution. As other known CSs, MsCS functions as a dimer, and each monomer consists of two domains, a large domain and a small domain. We also determined the structure of the complex with acetyl-CoA and revealed the acetyl-CoA binding mode of MsCS. Structural comparison of MsCS with another CS in complex with oxaloacetate enabled us to predict the oxaloacetate binding site. Moreover, we performed inhibitory kinetic analyses of MsCS, and showed that the protein is inhibited by citrate and ATP by competitive and non-competitive inhibition modes, respectively, but not by NADH. Based on these results, we suggest that MsCS belongs to the type-I CS with structural and biochemical properties similar to those of CSs involved in the conventional TCA cycle.


Assuntos
Proteínas Arqueais/química , Citrato (si)-Sintase/química , Sulfolobaceae/enzimologia , Acetilcoenzima A/metabolismo , Proteínas Arqueais/metabolismo , Domínio Catalítico , Citrato (si)-Sintase/metabolismo , Cristalografia por Raios X , Cinética , Modelos Moleculares , Conformação Proteica , Sulfolobaceae/química , Sulfolobaceae/metabolismo
19.
Biochem Biophys Res Commun ; 517(3): 399-406, 2019 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-31378370

RESUMO

Mycobacterium smegmatis is a good model for studying the physiology and pathogenesis of Mycobacterium tuberculosis due to its genetic similarity. As methionine biosynthesis exists only in microorganisms, the enzymes involved in methionine biosynthesis can be a potential target for novel antibiotics. Homoserine O-acetyltransferase from M. smegmatis (MsHAT) catalyzes the transfer of acetyl-group from acetyl-CoA to homoserine. To investigate the molecular mechanism of MsHAT, we determined its crystal structure in apo-form and in complex with either CoA or homoserine and revealed the substrate binding mode of MsHAT. A structural comparison of MsHAT with other HATs suggests that the conformation of the α5 to α6 region might influence the shape of the dimer. In addition, the active site entrance shows an open or closed conformation and might determine the substrate binding affinity of HATs.


Assuntos
Acetilcoenzima A/química , Acetiltransferases/química , Apoproteínas/química , Proteínas de Bactérias/química , Homosserina/química , Mycobacterium smegmatis/química , Acetilcoenzima A/metabolismo , Acetiltransferases/genética , Acetiltransferases/metabolismo , Sequência de Aminoácidos , Apoproteínas/genética , Apoproteínas/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Domínio Catalítico , Clonagem Molecular , Cristalografia por Raios X , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Haemophilus influenzae/química , Haemophilus influenzae/enzimologia , Haemophilus influenzae/genética , Homosserina/metabolismo , Cinética , Leptospira interrogans/química , Leptospira interrogans/enzimologia , Leptospira interrogans/genética , Modelos Moleculares , Mycobacteriaceae/química , Mycobacteriaceae/enzimologia , Mycobacteriaceae/genética , Mycobacterium abscessus/química , Mycobacterium abscessus/enzimologia , Mycobacterium abscessus/genética , Mycobacterium smegmatis/enzimologia , Mycobacterium smegmatis/genética , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Especificidade por Substrato
20.
Biochem Biophys Res Commun ; 518(3): 479-485, 2019 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-31427080

RESUMO

Isoprenoids comprise a diverse group of natural products with a broad range of metabolic functions. Isoprenoids are synthesized from prenyl pyrophosphates by prenyltransferases that catalyze the isoprenoid chain-elongation process to different chain lengths. We hereby present the crystal structure of geranylgeranyl pyrophosphate synthase from the marine flavobacterium Nonlabens dokdonensis DSW-6 (NdGGPPS). NdGGPPS forms a hexamer composed of homodimeric trimer, and the monomeric structure is composed of 15 α-helices (α1-α15). In this structure, we observed the binding of one pyrophosphate molecule and two glycerol molecules that mimicked substrate binding to the enzyme. The substrate binding site of NdGGPPS contains large hydrophobic residues such as Phe, His and Tyr, and structural and amino acids sequence analyses thereof suggest that the protein belongs to the short-chain prenyltransferase family.


Assuntos
Proteínas de Bactérias/química , Flavobacteriaceae/química , Geranil-Geranildifosfato Geranil-Geraniltransferase/química , Sequência de Aminoácidos , Cristalografia por Raios X , Modelos Moleculares , Conformação Proteica , Conformação Proteica em alfa-Hélice , Multimerização Proteica , Alinhamento de Sequência
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