Characterization of the N-acetyl-α-D-glucosaminyl l-malate synthase and deacetylase functions for bacillithiol biosynthesis in Bacillus anthracis .
Characterization of the N-acetyl-α-D-glucosaminyl l-malate synthase and deacetylase functions for bacillithiol biosynthesis in Bacillus anthracis .
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DOI：
10.1021/bi100698n
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发表时间：
2010-09-28
期刊：
影响因子：
2.9
通讯作者：
Claiborne A
中科院分区：
文献类型：
--
作者：
Parsonage D;Newton GL;Holder RC;Wallace BD;Paige C;Hamilton CJ;Dos Santos PC;Redinbo MR;Reid SD;Claiborne A
芽孢杆菌硫醇（Cys-GlcN-苹果酸，BSH）最近被鉴定为炭疽杆菌、金黄色葡萄球菌和其他几种缺乏谷胱甘肽和霉菌硫醇的革兰氏阳性菌中的新型低分子量硫醇。我们现在已经鉴定了炭疽杆菌中 BSH 生物合成途径的前两种酶，它们结合起来从 UDP-GlcNAc 和 L-苹果酸产生 α-D-葡萄糖胺基 L-苹果酸 (GlcN-苹果酸)。 GlcNAc-苹果酸中间体的结构已确定，BaBshA 糖基转移酶（→GlcNAc-苹果酸）和 BaBshB 脱乙酰酶（→GlcN-苹果酸）的动力学参数也已确定。 BSH 是据报道仅有的两种含有苹果酸苷的天然产物之一，并且在这项工作中以 3.3 Å 分辨率确定了 BaBshA-UDP-苹果酸三元复合物的晶体结构，确定了对 L-苹果酸而非其他 α-羟基酸作为受体底物的特异性识别很重要的几个活性位点相互作用。与报道的 GlcNAc-1-D-肌醇-3-磷酸合酶 (MshA) apo 和三元复合物形式的结构形成鲜明对比，在相应的 BaBshA 形式的结构中没有观察到主要的构象变化。正如预测的那样，缺乏 BshA 糖基转移酶的炭疽芽孢杆菌突变株无法产生 BSH。炭疽芽孢杆菌 bshA 基因座 (BA1558) 已在转座子位点杂交研究中被鉴定为生长、孢子形成或发芽所需的，这表明 BSH 的生物合成可以代表开发针对炭疽芽孢杆菌等革兰氏阳性病原体具有广谱活性的新型抗菌药物的目标。在芽孢杆菌中发挥硫醇氧化还原缓冲和稳态功能的代谢物尚不清楚，我们根据这项工作和其他最近的工作提出了一幅合成图。
Bacillithiol (Cys-GlcN-malate, BSH) has recently been identified as a novel low-molecular-weight thiol in Bacillus anthracis, Staphylococcus aureus, and several other Gram-positive bacteria lacking glutathione and mycothiol. We have now characterized the first two enzymes for the BSH biosynthetic pathway in B. anthracis, which combine to produce α-D-glucosaminyl L-malate (GlcN-malate) from UDP-GlcNAc and L-malate. The structure of the GlcNAc-malate intermediate has been determined, as have the kinetic parameters for the BaBshA glycosyltransferase (→GlcNAc-malate) and the BaBshB deacetylase (→GlcN-malate). BSH is one of only two natural products reported to contain a malyl glycoside, and the crystal structure of the BaBshA-UDP-malate ternary complex, determined in this work at 3.3 Å resolution, identifies several active-site interactions important for the specific recognition of L-malate, but not other α-hydroxyacids, as acceptor substrate. In sharp contrast to the structures reported for the GlcNAc—1-D-myo-inositol-3-phosphate synthase (MshA) apo and ternary complex forms, there is no major conformational change observed in the structures of the corresponding BaBshA forms. A mutant strain of B. anthracis deficient in the BshA glycosyltransferase fails to produce BSH, as predicted. This B. anthracis bshA locus (BA1558) has been identified in a transposon site hybridization study as required for growth, sporulation, or germination, suggesting that the biosynthesis of BSH could represent a target for development of novel antimicrobials with broad spectrum activity against Gram-positive pathogens like B. anthracis. The metabolites that function in thiol redox buffering and homeostasis in Bacillus are not well understood, and we present a composite picture based on this and other recent work.
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影响因子：
2.9
作者：
CALENDAR, R;BERG, P
通讯作者：
BERG, P
影响因子：
5.8
作者：
Gouet, P;Courcelle, E;Métoz, F
通讯作者：
Métoz, F
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
3.2
作者：
Cao, M;Bernat, BA;Helmann, JD
通讯作者：
Helmann, JD
DOI：
10.1107/s0907444909052925
发表时间：
2010-02
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Adams PD;Afonine PV;Bunkóczi G;Chen VB;Davis IW;Echols N;Headd JJ;Hung LW;Kapral GJ;Grosse-Kunstleve RW;McCoy AJ;Moriarty NW;Oeffner R;Read RJ;Richardson DC;Richardson JS;Terwilliger TC;Zwart PH
通讯作者：
Zwart PH