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1.
Acta Crystallogr D Struct Biol ; 73(Pt 5): 388-401, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28471364

RESUMO

The laccase from Steccherinum murashkinskyi is a member of the large family of multicopper oxidases that catalyze the oxidation of a wide range of organic and inorganic substrates, accompanied by the reduction of dioxygen to water. The reducing properties of X-ray radiation and the high quality of the laccase crystals allow the study of the catalytic reduction of dioxygen to water directly in a crystal. A series of diffraction data sets with increasing absorbed radiation dose were collected from a single crystal of Steccherinum murashkinskyi laccase at 1.35 Šresolution. Changes in the active-site structure associated with the reduction of molecular oxygen to water on increasing the absorbed dose of ionizing radiation were detected. The structures in the series are mixtures of different states of the enzyme-substrate complex. Nevertheless, it was possible to interpret these structures as complexes of various oxygen ligands with copper ions in different oxidation states. The results allowed the mechanism of oxygen reduction catalyzed by laccases to be refined.


Assuntos
Lacase/metabolismo , Oxigênio/metabolismo , Polyporales/enzimologia , Água/metabolismo , Biocatálise/efeitos da radiação , Domínio Catalítico/efeitos da radiação , Cristalografia por Raios X , Lacase/química , Modelos Moleculares , Oxirredução/efeitos da radiação , Polyporales/química , Polyporales/efeitos da radiação , Conformação Proteica/efeitos da radiação , Raios X
2.
Acta Crystallogr D Struct Biol ; 72(Pt 2): 203-10, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26894668

RESUMO

Uridine phosphorylase (UP; EC 2.4.2.3), a key enzyme in the pyrimidine-salvage pathway, catalyzes the reversible phosphorolysis of uridine to uracil and ribose 1-phosphate. The structure of the C212S mutant of uridine phosphorylase from the facultatively aerobic Gram-negative γ-proteobacterium Shewanella oneidensis MR-1 (SoUP) was determined at 1.68 Šresolution. A comparison of the structures of the mutant and the wild-type enzyme showed that one dimer in the mutant hexamer differs from all other dimers in the mutant and wild-type SoUP (both in the free form and in complex with uridine). The key difference is the `maximum open' state of one of the subunits comprising this dimer, which has not been observed previously for uridine phosphorylases. Some conformational features of the SoUP dimer that provide access of the substrate into the active site are revealed. The binding of the substrate was shown to require the concerted action of two subunits of the dimer. The changes in the three-dimensional structure induced by the C212S mutation account for the lower affinity of the mutant for inorganic phosphate, while the affinity for uridine remains unchanged.


Assuntos
Proteínas de Bactérias/química , Shewanella/enzimologia , Uridina Fosforilase/química , Domínio Catalítico , Cristalografia por Raios X , Ligação de Hidrogênio , Cinética , Modelos Moleculares , Ligação Proteica , Estrutura Quaternária de Proteína , Estrutura Secundária de Proteína , Especificidade por Substrato , Uridina/química
3.
Acta Crystallogr F Struct Biol Commun ; 71(Pt 12): 1465-9, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26625287

RESUMO

Laccases belong to the class of multicopper oxidases catalyzing the oxidation of phenols accompanied by the reduction of molecular oxygen to water without the formation of hydrogen peroxide. The activity of laccases depends on the number of Cu atoms per enzyme molecule. The structure of type 2 copper-depleted laccase from Botrytis aclada has been solved previously. With the aim of obtaining the structure of the native form of the enzyme, crystals of the depleted laccase were soaked in Cu(+)- and Cu(2+)-containing solutions. Copper ions were found to be incorporated into the active site only when Cu(+) was used. A comparative analysis of the native and depleted forms of the enzymes was performed.


Assuntos
Botrytis/enzimologia , Cobre/metabolismo , Lacase/metabolismo , Sequência de Aminoácidos , Cristalização , Cristalografia por Raios X , Íons , Lacase/química , Modelos Moleculares , Dados de Sequência Molecular , Temperatura
4.
Acta Crystallogr D Biol Crystallogr ; 71(Pt 5): 1087-94, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25945574

RESUMO

Octahaem cytochrome c nitrite reductase from the bacterium Thioalkalivibrio nitratireducens catalyzes the reduction of nitrite to ammonium and of sulfite to sulfide. The reducing properties of X-ray radiation and the high quality of the enzyme crystals allow study of the catalytic reaction of cytochrome c nitrite reductase directly in a crystal of the enzyme, with the reaction being induced by X-rays. Series of diffraction data sets with increasing absorbed dose were collected from crystals of the free form of the enzyme and its complexes with nitrite and sulfite. The corresponding structures revealed gradual changes associated with the reduction of the catalytic haems by X-rays. In the case of the nitrite complex the conversion of the nitrite ions bound in the active sites to NO species was observed, which is the beginning of the catalytic reaction. For the free form, an increase in the distance between the oxygen ligand bound to the catalytic haem and the iron ion of the haem took place. In the case of the sulfite complex no enzymatic reaction was detected, but there were changes in the arrangement of the active-site water molecules that were presumably associated with a change in the protonation state of the sulfite ions.


Assuntos
Citocromos a1/química , Citocromos a1/metabolismo , Citocromos c1/química , Citocromos c1/metabolismo , Ectothiorhodospiraceae/enzimologia , Heme/química , Nitrato Redutases/química , Nitrato Redutases/metabolismo , Nitritos/metabolismo , Conformação Proteica/efeitos da radiação , Sulfitos/metabolismo , Domínio Catalítico , Cristalografia por Raios X , Citocromos a1/efeitos da radiação , Citocromos c1/efeitos da radiação , Ectothiorhodospiraceae/efeitos da radiação , Modelos Moleculares , Nitrato Redutases/efeitos da radiação , Nitritos/química , Nitritos/efeitos da radiação , Ligação Proteica , Efeitos da Radiação , Especificidade por Substrato , Sulfitos/química , Sulfitos/efeitos da radiação , Raios X
7.
Acta Crystallogr D Biol Crystallogr ; 69(Pt 6): 991-6, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23695243

RESUMO

Ribonuclease from Bacillus intermedius (binase) is a small basic protein with antitumour activity. The three-dimensional structure of the binase mutant form Glu43Ala/Phe81Ala was determined at 1.98 Å resolution and its functional properties, such as the kinetic parameters characterizing the hydrolysis of polyinosinic acid and cytotoxicity towards Kasumi-1 cells, were investigated. In all crystal structures of binase studied previously the characteristic dimer is present, with the active site of one subunit being blocked owing to interactions within the dimer. In contrast to this, the new mutant form is not dimeric in the crystal. The catalytic efficiency of the mutant form is increased 1.7-fold and its cytotoxic properties are enhanced compared with the wild-type enzyme.


Assuntos
Endorribonucleases/química , Endorribonucleases/genética , Proteínas Mutantes/química , Proteínas Mutantes/genética , Poli I/metabolismo , Bacillus/química , Bacillus/enzimologia , Bacillus/genética , Catálise , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Endorribonucleases/metabolismo , Humanos , Cinética , Modelos Moleculares , Mutagênese , Proteínas Mutantes/metabolismo , Difração de Raios X
8.
Acta Crystallogr Sect F Struct Biol Cryst Commun ; 68(Pt 12): 1440-7, 2012 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-23192021

RESUMO

DNA ligases join single-strand breaks in double-stranded DNA by catalyzing the formation of a phosphodiester bond between adjacent 5'-phosphate and 3'-hydroxyl termini. Their function is essential for maintaining genome integrity in the replication, recombination and repair of DNA. High flexibility is important for the function of DNA ligase molecules. Two types of overall conformations of archaeal DNA ligase that depend on the relative position of the OB-fold domain have previously been revealed: closed and open extended conformations. The structure of ATP-dependent DNA ligase from Thermococcus sp. 1519 (LigTh1519) in the crystalline state determined at a resolution of 3.02 Šshows a new relative arrangement of the OB-fold domain which is intermediate between the positions of this domain in the closed and the open extended conformations of previously determined archaeal DNA ligases. However, small-angle X-ray scattering (SAXS) measurements indicate that in solution the LigTh1519 molecule adopts either an open extended conformation or both an intermediate and an open extended conformation with the open extended conformation being dominant.


Assuntos
Trifosfato de Adenosina/metabolismo , DNA Ligases/química , DNA Arqueal/metabolismo , Thermococcus/enzimologia , Trifosfato de Adenosina/química , Proteínas Arqueais/química , Proteínas Arqueais/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Quebras de DNA de Cadeia Simples , DNA Ligase Dependente de ATP , DNA Ligases/metabolismo , Modelos Moleculares , Dobramento de Proteína , Espalhamento a Baixo Ângulo , Thermococcus/classificação
9.
Biochemistry (Mosc) ; 77(10): 1190-8, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23157299

RESUMO

The gene xylE encoding endo-1,4-ß-xylanase from the 10th family of glycosyl hydrolases produced by the mycelial fungus Penicillium canescens has been expressed under the control of the strong promoter of the bgaS gene encoding ß-galactosidase from P. canescens. As a result, a strain-producer of endoxylanase XylE was developed. The recombinant enzyme was isolated and purified to homogeneity with specific activity of 50 U/mg. The physicochemical and biochemical properties of the endoxylanase were studied. The maximal enzymatic activity was observed at pH 6.0 and 70°C. Endoxylanase XylE was shown to be a highly thermostable enzyme with half-inactivation period τ(1/2) of 7 h at 60°C. The kinetic parameters were 0.52 mg/ml (K(m)) and 75 µmol/min per mg (V(max)) using birch xylan as the substrate. Crystals of endoxylonase XylE were obtained, and the 3D structure was solved at 1.47 Å resolution. The 3D structure of an endo-1,4-ß-xylanase from the 10th family containing carbohydrate and unique cyclic structure located at the C-terminus of the polypeptide chain was obtained for the first time.


Assuntos
Endo-1,4-beta-Xilanases/genética , Endo-1,4-beta-Xilanases/metabolismo , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Penicillium/enzimologia , Penicillium/genética , Proteínas Recombinantes/metabolismo , Simportadores/química , Simportadores/metabolismo , Cristalografia por Raios X , Endo-1,4-beta-Xilanases/química , Endo-1,4-beta-Xilanases/isolamento & purificação , Proteínas de Escherichia coli/genética , Proteínas Recombinantes/genética , Especificidade por Substrato , Simportadores/genética
10.
Acta Crystallogr Sect F Struct Biol Cryst Commun ; 68(Pt 11): 1275-8, 2012 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23143231

RESUMO

Prolidases are peptidases that are specific for dipeptides with proline as the second residue. The structure of recombinant prolidase from the hyperthermophilic archaeon Thermococcus sibiricus (Tsprol) was determined at 2.6 Šresolution. The homodimer of Tsprol is characterized by a complete lack of interactions between the N- and C-terminal domains of the two subunits and hence can be considered to be the most open structure when compared with previously structurally studied prolidases. This structure exists owing to intermolecular coordination bonds between cadmium ions derived from the crystallization solution and histidine residues of a His tag and aspartate and glutamate residues, which link the dimers to each other. This linking leads to the formation of a crystal with a loose packing of protein molecules and low resistance to mechanical influence and temperature increase.


Assuntos
Proteínas Arqueais/química , Dipeptidases/química , Thermococcus/enzimologia , Domínio Catalítico , Cristalografia por Raios X , Modelos Moleculares , Domínios e Motivos de Interação entre Proteínas , Estrutura Quaternária de Proteína , Estrutura Secundária de Proteína , Subunidades Proteicas/química , Proteínas Recombinantes/química
11.
Artigo em Inglês | MEDLINE | ID: mdl-22297989

RESUMO

DNA ligases join single-strand breaks in double-stranded DNA by catalyzing the formation of a phosphodiester bond between adjacent 5'-phosphate and 3'-hydroxyl termini. Their function is essential to maintain the integrity of the genome in DNA replication, recombination and repair. A recombinant ATP-dependent DNA ligase from the hyperthermophilic anaerobic archaeon Thermococcus sibiricus was expressed in Escherichia coli and purified. Crystals were grown by vapour diffusion using the hanging-drop method with 17%(w/v) PEG 4000 and 8.5%(v/v) 2-propanol as precipitants. A diffraction experiment was performed with a single crystal, which diffracted X-rays to 3.0 Å resolution. The crystal belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 58.590, b = 87.540, c = 126.300 Å.


Assuntos
DNA Ligases/química , Thermococcus/enzimologia , Cristalização , Cristalografia por Raios X , DNA Ligase Dependente de ATP , DNA Ligases/genética , DNA Ligases/isolamento & purificação , Estabilidade Enzimática , Expressão Gênica , Temperatura
12.
Artigo em Inglês | MEDLINE | ID: mdl-20516592

RESUMO

Alcohol dehydrogenases belong to the oxidoreductase family and play an important role in a broad range of physiological processes. They catalyze the cofactor-dependent reversible oxidation of alcohols to the corresponding aldehydes or ketones. The NADP-dependent short-chain alcohol dehydrogenase TsAdh319 from the thermophilic archaeon Thermococcus sibiricus was overexpressed, purified and crystallized. Crystals were obtained using the hanging-drop vapour-diffusion method using 25%(w/v) polyethylene glycol 3350 pH 7.5 as precipitant. The crystals diffracted to 1.68 A resolution and belonged to space group I222, with unit-cell parameters a = 55.63, b = 83.25, c = 120.75 A.


Assuntos
Álcool Desidrogenase/química , Thermococcus/enzimologia , Álcool Desidrogenase/genética , Álcool Desidrogenase/isolamento & purificação , Cristalização , Cristalografia por Raios X , Estabilidade Enzimática , Expressão Gênica , Temperatura
13.
Acta Crystallogr D Biol Crystallogr ; 65(Pt 12): 1315-25, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19966418

RESUMO

NAD(+)-dependent formate dehydrogenase (FDH) catalyzes the oxidation of formate ion to carbon dioxide coupled with the reduction of NAD(+) to NADH. The crystal structures of the apo and holo forms of FDH from the methylotrophic bacterium Moraxella sp. C-1 (MorFDH) are reported at 1.96 and 1.95 A resolution, respectively. MorFDH is similar to the previously studied FDH from the bacterium Pseudomonas sp. 101 in overall structure, cofactor-binding mode and active-site architecture, but differs in that the eight-residue-longer C-terminal fragment is visible in the electron-density maps of MorFDH. MorFDH also differs in the organization of the dimer interface. The holo MorFDH structure supports the earlier hypothesis that the catalytic residue His332 can form a hydrogen bond to both the substrate and the transition state. Apo MorFDH has a closed conformation of the interdomain cleft, which is unique for an apo form of an NAD(+)-dependent dehydrogenase. A comparison of the structures of bacterial FDH in open and closed conformations allows the differentiation of the conformational changes associated with cofactor binding and domain motion and provides insights into the mechanism of the closure of the interdomain cleft in FDH. The C-terminal residues 374-399 and the substrate (formate ion) or inhibitor (azide ion) binding are shown to play an essential role in the transition from the open to the closed conformation.


Assuntos
Formiato Desidrogenases/química , Moraxella/enzimologia , Sequência de Aminoácidos , Apoenzimas/química , Apoenzimas/metabolismo , Sítios de Ligação , Biocatálise , Cristalografia por Raios X , Formiato Desidrogenases/metabolismo , Holoenzimas/química , Holoenzimas/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Multimerização Proteica , Estrutura Quaternária de Proteína , Estrutura Terciária de Proteína , Alinhamento de Sequência , Especificidade por Substrato
14.
Biochemistry (Mosc) ; 74(8): 834-41, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19817682

RESUMO

It is supposed that alpha,gamma-diketo acids (DKAs) inhibit the activity of hepatitis C virus RNA-dependent RNA polymerase (RdRP HCV) via chelation of catalytic magnesium ions in the active center of the enzyme. However, DKAs display noncompetitive mode of inhibition with respect to NTP substrate, which contradicts the proposed mechanism. We have examined the NTP substrate entry channel and the active site of RdRP HCV for their possible interaction with DKAs. The substitutions R48A, K51A, and R222A greatly facilitated RdRP inhibition by DKAs and simultaneously increased K(m) values for UTP substrate. Interestingly, C223A was the only one of a number of substitutions that decreased K(m)(UTP) but facilitated the inhibitory action of DKAs. The findings allowed us to model an enzyme-inhibitor complex. According to the proposed model, DKAs introduce an additional Mg2+ ion into the active site of the enzyme at a stage of phosphodiester bond formation, which results in displacement of the NTP substrate triphosphate moiety to a catalytically inactive binding mode. This mechanism, in contrast to the currently adopted one, explains the noncompetitive mode of inhibition.


Assuntos
Aminobutiratos/química , Inibidores Enzimáticos/química , Hepacivirus/enzimologia , RNA Polimerase Dependente de RNA/química , Proteínas não Estruturais Virais/química , Aminobutiratos/síntese química , Domínio Catalítico , Inibidores Enzimáticos/síntese química , Cinética , Fenilbutiratos , RNA Polimerase Dependente de RNA/genética , RNA Polimerase Dependente de RNA/metabolismo , Especificidade por Substrato , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo
15.
Acta Naturae ; 1(3): 89-93, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22649619

RESUMO

The crystal structure of the ternary complex of NAD+-dependent formate dehydrogenase from the methylotrophic bacterium Moraxella sp. C-1 with the cofactor (NAD+) and the inhibitor (azide ion) was established at 1.1 A resolution. The complex mimics the structure of the transition state of the enzymatic reaction. The structure was refined with anisotropic displacitalicents parameters for non-hydrogen atoms to a R factor of 13.4%. Most of the nitrogen, oxygen, and carbon atoms were distinguished based on the analysis of the titalicperature factors and electron density peaks, with the result that side-chain rotamers of histidine residues and most of asparagine and glutamine residues were unambiguously determined. A comparative analysis of the structure of the ternary complex determined at the atomic resolution and the structure of this complex at 1.95 A resolution was performed. In the atomic resolution structure, the covalent bonds in the nicotinamide group are somewhat changed in agreitalicent with the results of quantum mechanical calculations, providing evidence that the cofactor acquires a bipolar form in the transition state of the enzymatic reaction.

16.
Biochemistry (Mosc) ; 73(2): 164-70, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18298372

RESUMO

A new procedure for isolation of cytochrome c nitrite reductase from the haloalkaliphilic bacterium Thioalkalivibrio nitratireducens increasing significantly the yield of the purified enzyme is presented. The enzyme is isolated from the soluble fraction of the cell extract as a hexamer, as shown by gel filtration chromatography and small angle X-ray scattering analysis. Thermostability of the hexameric form of the nitrite reductase is characterized in terms of thermoinactivation and thermodenaturation.


Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/isolamento & purificação , Citocromos a1/química , Citocromos a1/isolamento & purificação , Citocromos c1/química , Citocromos c1/isolamento & purificação , Ectothiorhodospiraceae/enzimologia , Nitrato Redutases/química , Nitrato Redutases/isolamento & purificação , Cromatografia em Gel , Cromatografia por Troca Iônica , Estabilidade Enzimática , Espalhamento a Baixo Ângulo , Temperatura , Difração de Raios X
17.
Biochemistry (Mosc) ; 72(1): 21-8, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17309433

RESUMO

Substrate specificity of Escherichia coli thymidine phosphorylase to thymidine derivatives modified at 5' -, 3' -, and 2' ,3' - positions of the sugar moiety was studied. Equilibrium and kinetic constants (K(m), K(I), k(cat)) of the phosphorolysis reaction have been determined for 20 thymidine analogs. The results are compared with X-ray and molecular dynamics data. The most important hydrogen bonds in the enzyme-substrate complex are revealed.


Assuntos
Substituição de Aminoácidos , Escherichia coli/enzimologia , Timidina Fosforilase/química , Timidina/metabolismo , Domínio Catalítico , Cristalografia por Raios X , Concentração de Íons de Hidrogênio , Estrutura Molecular , Nucleosídeos/metabolismo , Relação Estrutura-Atividade , Especificidade por Substrato , Timidina Fosforilase/metabolismo
18.
Biochemistry (Mosc) ; 71(9): 1021-6, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17009957

RESUMO

Pyrogallol reversibly and noncompetitively inhibits the activity of the hepatitis C RNA-dependent RNA polymerase. Based on molecular modeling of the inhibitor binding in the active site of the enzyme, the inhibition was suggested to be realized via chelation of two magnesium cations involved in the catalysis at the stage of the phosphoryl residue transfer. The proposed model allowed us to purposefully synthesize new derivatives with higher inhibitory capacity.


Assuntos
Hepacivirus/enzimologia , Pirogalol/análogos & derivados , Pirogalol/farmacologia , RNA Polimerase Dependente de RNA/antagonistas & inibidores , Aminobutiratos/farmacologia , Sítios de Ligação , Quelantes/farmacologia , Magnésio/química , Modelos Moleculares , Fenilbutiratos
19.
Artigo em Inglês | MEDLINE | ID: mdl-16511304

RESUMO

A novel cytochrome c nitrite reductase (TvNiR) was isolated from the haloalkalophilic bacterium Thioalkalivibrio nitratireducens. The enzyme catalyses nitrite and hydroxylamine reduction, with ammonia as the only product of both reactions. It consists of 525 amino-acid residues and contains eight haems c. TvNiR crystals were grown by the hanging-drop vapour-diffusion technique. The crystals display cubic symmetry and belong to space group P2(1)3, with unit-cell parameter a = 194 A. A native data set was obtained to 1.5 A resolution. The structure was solved by the SAD technique using the data collected at the Fe absorption peak wavelength.


Assuntos
Citocromos a1/química , Citocromos c1/química , Ectothiorhodospiraceae/enzimologia , Nitrato Redutases/química , Cristalização/métodos , Cristalografia por Raios X , Heme/análise
20.
Acta Crystallogr D Biol Crystallogr ; 61(Pt 3): 230-5, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15735332

RESUMO

Glutamate decarboxylase (GAD) is a pyridoxal enzyme that catalyzes the conversion of L-glutamate into gamma-aminobutyric acid and carbon dioxide. The Escherichia coli enzyme exists as two isozymes, referred to as GADalpha and GADbeta. Crystals of the complex of the recombinant isozyme GADalpha with glutarate as a substrate analogue were grown in space group R3, with unit-cell parameters a = b = 117.1, c = 196.4 angstroms. The structure of the enzyme was solved by the molecular-replacement method and refined at 2.05 angstroms resolution to an R factor of 15.1% (R(free) = 19.9%). The asymmetric unit contains a dimer consisting of two subunits of the enzyme related by a noncrystallographic twofold axis which is perpendicular to and intersects a crystallographic threefold axis. The dimers are related by a crystallographic threefold axis to form a hexamer. The active site of each subunit is formed by residues of the large domains of both subunits of the dimer. The coenzyme pyridoxal phosphate (PLP) forms an aldimine bond with Lys276. The glutarate molecule bound in the active site of the enzyme adopts two conformations with equal occupancies. One of the two carboxy groups of the glutarate occupies the same position in both conformations and forms hydrogen bonds with the N atom of the main chain of Phe63 and the side chain of Thr62 of one subunit and the side chains of Asp86 and Asn83 of the adjacent subunit of the dimer. Apparently, it is in this position that the distal carboxy group of the substrate would be bound by the enzyme, thus providing recognition of glutamic acid by the enzyme.


Assuntos
Escherichia coli/enzimologia , Glutamato Descarboxilase/química , Glutaratos/química , Glutamato Descarboxilase/isolamento & purificação , Modelos Moleculares , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação
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