Structural basis of the substrate recognition of hydrazidase isolated from Microbacterium sp. strain HM58-2, which catalyzes acylhydrazide compounds as its sole carbon source
Structural basis of the substrate recognition of hydrazidase isolated from Microbacterium sp. strain HM58-2, which catalyzes acylhydrazide compounds as its sole carbon source
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从微杆菌属分离的酰肼酶底物识别的结构基础。
DOI：
10.1016/j.bbrc.2016.11.148
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发表时间：
2017
影响因子：
3.1
通讯作者：
Takaya N. and Yajima S.
中科院分区：
文献类型：
--
作者：
Akiyama T.;Ishii M.;Takuwa A.;Oinuma K.;Sasaki Y.;Takaya N. and Yajima S.
酰肼酶是一种半个世纪来一直未被发现的酶。然而，最近，它被纯化，其编码基因被克隆。菌株HM 58 -2以酰肼作为其唯一碳源生长;它产生酰肼酶并将酰肼降解为乙酸盐和酰肼。细菌酰肼酶属于酰胺酶特征酶家族，并且含有Ser-cisSer-Lys催化基序。肼和碳酸缩合生成各种酰肼，其中一些是合成药物和其他有用化学品的原料。虽然天然酰肼化合物已被确定，酰肼的代谢系统还没有完全了解。本文报道了微杆菌属（Microbacteriumsp.）菌株HM 58 -2。活性位点被揭示由Ser-cisSer-Lys催化三联体组成，其中Ser 179与底物的羰基碳形成共价键。4-羟基苯甲酸酰肼结合到S179 A突变体，显示由三个骨架酰胺基团组成的含氧阴离子孔。此外，在酰胺酶家族的非保守区的H336可能定义的底物特异性，这是由突变分析证实。野生型脱辅基酶的结构揭示了一个身份不明的分子共价结合到S179，代表四面体中间体。
Hydrazidase was an enzyme that remained unidentified for a half century. However, recently, it was purified, and its encoding gene was cloned.Microbacteriumsp. strain HM58-2 grows with acylhydrazides as its sole carbon source; it produces hydrazidase and degrades acylhydrazides to acetate and hydrazides. The bacterial hydrazidase belongs to the amidase signature enzyme family and contains a Ser-cisSer-Lys catalytic motif. The condensation of hydrazine and carbonic acid produces various hydrazides, some of which are raw materials for synthesizing pharmaceuticals and other useful chemicals. Although natural hydrazide compounds have been identified, the metabolic systems for hydrazides are not fully understood. Here, we report the crystal structure of hydrazidase fromMicrobacteriumsp. strain HM58-2. The active site was revealed to consist of a Ser-cisSer-Lys catalytic triad, in which Ser179 forms a covalent bond with a carbonyl carbon of the substrate. 4-Hydroxybenzoic acid hydrazide bound to the S179A mutant, showing an oxyanion hole composed of the three backbone amide groups. Furthermore, H336 in the non-conserved region in the amidase family may define the substrate specificity, which was confirmed by mutation analysis. A wild-type apoenzyme structure revealed an unidentified molecule covalently bound to S179, representing a tetrahedral intermediate.