X-ray crystal structure of the streptococcal specific phage lysin PlyC

Publication (PNAS) Bacteriophages deploy lysins that degrade the bacterial cell wall and facilitate virus egress from the host. When applied exogenously, these enzymes destroy susceptible microbes and, accordingly, have potential as therapeutic agents. The most potent lysin identified to date is PlyC, an enzyme assembled from two components (PlyCA and PlyCB) that is specific for streptococcal species. Here the structure of the PlyC holoenzyme reveals that a single PlyCA moiety is tethered to a ring-shaped assembly of eight PlyCB molecules. Structure-guided mutagenesis reveals that the bacterial cell wall binding is achieved through a cleft on PlyCB. Unexpectedly, our structural data reveal that PlyCA contains a glycoside hydrolase domain in addition to the previously recognized cysteine, histidine-dependent amidohydrolases/peptidases catalytic domain. The presence of eight cell wall-binding domains together with two catalytic domains may explain the extraordinary potency of the PlyC holoenyzme toward target bacteria.
This entry contains two diffraction datasets:

PlyCB (PDB ID: 4F87)
PlyC (PDB ID: 4F88)

Automatically generated on 2015-06-02 06:39:07 by https://github.com/steveandroulakis/mytardis-uploader To cite this data use the following DOI: 10.4225/52/557FAA5E63100

发表于《美国国家科学院院刊》（PNAS）的研究表明：噬菌体可分泌溶素，降解细菌细胞壁并协助病毒从宿主细胞中释放。若外源施加这类酶制剂，可杀灭易感微生物，因此具备开发为治疗制剂的潜力。目前已发现的活性最强的溶素为PlyC，该酶由PlyCA与PlyCB两个亚基组装而成，仅对链球菌属细菌具有特异性。本研究解析的PlyC全酶结构显示，单个PlyCA亚基与由8个PlyCB分子构成的环状组装体相连。基于结构的诱变实验证实，细菌细胞壁的结合通过PlyCB上的裂隙实现。令人意外的是，我们的结构数据显示，PlyCA除包含此前已确认的半胱氨酸、组氨酸依赖型酰胺水解酶/肽酶催化结构域外，还含有一个糖苷水解酶结构域。8个细胞壁结合结构域与2个催化结构域的协同存在，或许正是PlyC全酶对靶标细菌展现出超强活性的原因。

本数据集包含两组衍射数据：
PlyCB（蛋白质数据库（Protein Data Bank, PDB）编号：4F87）
PlyC（蛋白质数据库（Protein Data Bank, PDB）编号：4F88）

本数据集于2015年6月2日06:39:07由https://github.com/steveandroulakis/mytardis-uploader自动生成。引用该数据集请使用以下DOI：10.4225/52/557FAA5E63100