Bradshaw William J, Kirby Jonathan M, Roberts April K, Shone Clifford C, Acharya K Ravi
Department of Biology and Biochemistry, University of Bath, UK.
Public Health England, Salisbury, UK.
FEBS J. 2017 Dec;284(24):4343-4357. doi: 10.1111/febs.14310. Epub 2017 Nov 17.
Clostridium difficile is a burden to healthcare systems around the world, causing tens of thousands of deaths annually. The S-layer of the bacterium, a layer of protein found of the surface of cells, has received a significant amount of attention over the past two decades as a potential target to combat the growing threat presented by C. difficile infections. The S-layer contains a wide range of proteins, each of which possesses three cell wall-binding domains, while many also possess a "functional" region. Here, we present the high resolution structure of the functional region of one such protein, Cwp19 along with preliminary functional characterisation of the predicted glycoside hydrolase. Cwp19 has a TIM barrel fold and appears to possess a high degree of substrate selectivity. The protein also exhibits peptidoglycan hydrolase activity, an order of magnitude slower than that of lysozyme and is the first member of glycoside hydrolase-like family 10 to be characterised. This research goes some way to understanding the role of Cwp19 in the S-layer of C. difficile.
Structural data are available in the PDB under the accession numbers 5OQ2 and 5OQ3.
艰难梭菌是全球医疗系统的一大负担，每年导致数万人死亡。该细菌的S层是位于细胞表面的一层蛋白质，在过去二十年中，作为对抗艰难梭菌感染日益增长威胁的潜在靶点受到了大量关注。S层包含多种蛋白质，每种蛋白质都有三个细胞壁结合结构域，许多还具有一个“功能”区域。在此，我们展示了一种此类蛋白质Cwp19功能区域的高分辨率结构以及预测的糖苷水解酶的初步功能表征。Cwp19具有TIM桶状折叠结构，似乎具有高度的底物选择性。该蛋白质还表现出肽聚糖水解酶活性，比溶菌酶慢一个数量级，并且是糖苷水解酶样家族10中首个被表征的成员。这项研究在一定程度上有助于理解Cwp19在艰难梭菌S层中的作用。
结构数据可在蛋白质数据库（PDB）中获取，登录号为5OQ2和5OQ3。
