Crystal structure of the glycosidase family 73 peptidoglycan hydrolase FlgJ
Crystal structure of the glycosidase family 73 peptidoglycan hydrolase FlgJ
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DOI：
10.1016/j.bbrc.2009.01.186
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发表时间：
2009-03-27
影响因子：
3.1
通讯作者：
Murata, Kousaku
中科院分区：
文献类型：
--
作者：
Hashimoto, Wataru;Ochiai, Akihito;Murata, Kousaku
73家族的糖苷水解酶（Glycoside hydrolase， GH）在细菌细胞壁肽聚糖的降解中起着重要作用。鞭毛蛋白FlgJ含有N端结构域和c端结构域，分别负责鞭毛杆组装和肽聚糖水解。Sphingomonas sp. A1菌株FlgJ的c -末端结构域（SPH1045-C）是GH-73家族成员，在大肠杆菌中表达、纯化并鉴定。SPH1045-C在pH 6.0和37℃时表现出最有效的细菌细胞裂解活性。SPH1045-C的x射线晶体结构通过单波长异常衍射在1.74埃分辨率下测定。该酶由两个裂片a和p组成。裂片之间有一个深的间隙，可以容纳聚合物分子，这表明活性位点位于裂片中。虽然SPH1045-C在结构上与GH-22和GH-23溶菌酶家族具有同源性，但活性位点的亲核试剂/碱基残基的排列对每种肽聚糖水解酶都是特异性的。(C) 2009爱思唯尔公司版权所有。
Glycoside hydrolase (GH) categorized into family 73 plays an important role in degrading bacterial cell wall peptidoglycan. The flagellar protein FlgJ contains N- and C-terminal domains responsible for flagellar rod assembly and peptidoglycan hydrolysis, respectively. A member of family GH-73, the C-terminal domain (SPH1045-C) of FlgJ from Sphingomonas sp. strain A1 was expressed in Escherichia coli, purified, and characterized. SPH1045-C exhibited bacterial cell lytic activity most efficiently at pH 6.0 and 37 degrees C. The X-ray crystallographic structure of SPH1045-C was determined at 1.74 angstrom resolution by single-wavelength anomalous diffraction. The enzyme consists of two lobes, a and p. A deep cleft located between the two lobes can accommodate polymer molecules, suggesting that the active site is located in the cleft. Although SPH1045-C shows a structural homology with family GH-22 and GH-23 lysozymes, the arrangement of the nucleophile/base residue in the active site is specific to each peptidoglycan hydrolase. (C) 2009 Elsevier Inc. All rights reserved.