Henry Marine, Coffey Aidan, O' Mahony Jim, Sleator Roy D
Department of Biological Sciences, Cork Institute of Technology, Cork, Ireland.
Bioeng Bugs. 2011 Mar-Apr;2(2):88-95. doi: 10.4161/bbug.2.2.14138.
Given their potential as specific and natural biocontrol agents, bacteriophages and their associated proteins have become the focus of renewed attention over the last decade. The aim of this study was to use a comparative modelling approach to generate a predicted 3D structure for LysB; a 332 amino acid lipolytic enzyme encoded by the mycobacteriophage Ardmore. The GXSXG pentapeptide, characteristic of lipolytic enzymes, was located at amino acid position 166-170. The three absolutely conserved residues among mycobacteriophage LysB proteins were also identified in Ardmore LysB as Ser-168, Gly-203 and Pro-205. CATH analysis of Ardmore LysB revealed a mainly Beta classification, Beta Barrel architecture and a topology similar to maltoporin. This is unlike the α/β hydrolase structure reported for the D29 LysB protein and, in fact appears in only 3 other sequenced LysB homologues to date. A search for conserved motifs within the amino acid sequence of LysB revealed the presence of both a cutinase motif and a PE-PPE motif. This study presents an in silico 3D predictive model of Ardmore lysin and confirms the high diversity of mycobacteriophages LysB proteins both at the sequence (2D) and structural (predicted 3D) levels.
鉴于噬菌体及其相关蛋白作为特异性天然生物防治剂的潜力，在过去十年中，它们已成为重新受到关注的焦点。本研究的目的是使用比较建模方法生成LysB的预测三维结构；LysB是一种由分枝杆菌噬菌体阿德莫尔编码的332个氨基酸的脂解酶。脂解酶特有的GXSXG五肽位于第166 - 170位氨基酸处。在分枝杆菌噬菌体LysB蛋白中三个绝对保守的残基在阿德莫尔LysB中也被鉴定为Ser-168、Gly-203和Pro-205。对阿德莫尔LysB的CATH分析显示主要为β分类、β桶结构以及与麦芽糊精转运蛋白相似的拓扑结构。这与报道的D29 LysB蛋白的α/β水解酶结构不同，事实上，迄今为止在其他仅3个已测序的LysB同源物中也出现这种情况。在LysB氨基酸序列中搜索保守基序发现同时存在角质酶基序和PE-PPE基序。本研究提出了阿德莫尔溶素的计算机三维预测模型，并证实了分枝杆菌噬菌体LysB蛋白在序列（二维）和结构（预测三维）水平上的高度多样性。
