LysGH15B, the SH3b Domain of Staphylococcal Phage Endolysin LysGH15, Retains High Affinity to Staphylococci
LysGH15B, the SH3b Domain of Staphylococcal Phage Endolysin LysGH15, Retains High Affinity to Staphylococci
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LysGH15B 是葡萄球菌噬菌体内溶素 LysGH15 的 SH3b 结构域，与葡萄球菌保持高亲和力
DOI：
10.1007/s00284-011-0018-y
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发表时间：
2011-12-01
影响因子：
2.6
通讯作者：
Diao, Yuwen
中科院分区：
文献类型：
--
作者：
Gu, Jingmin;Lu, Rong;Diao, Yuwen
LysGH15是一种噬菌体内溶素，对金黄色葡萄球菌（尤其是耐甲氧西林）具有特别广泛的裂解谱。葡萄球菌(MRSA)。序列分析表明，该内溶素含有一个c端细胞壁结合域（SH3b），使其与宿主菌株结合。在本研究中，我们评估了SH3b结构域（LysGH15B）的底物结合亲和力。克隆了LysGH15B与绿色荧光蛋白（LysGH15B - gfp）的融合蛋白，并在大肠杆菌中表达。采用激光扫描共聚焦显微镜检测不同激发波长下处理细胞的荧光，测定LysGH15B-GFP与GFP的结合活性。我们发现，LysGH15B-GFP不仅产生绿色荧光，更重要的是，对葡萄球菌分离物，特别是MRSA具有特异性亲和力。相比之下，单个GFP没有显示出任何结合活性。高亲和力归因于LysGH15B部分，融合蛋白的结合活性对葡萄球菌具有特异性。本研究提供了对LysGH15的SH3b结构域的深入了解。特定的结合活性可能导致LysGH15B作为锚定装置，并为葡萄球菌的细胞表面附着提供了一种替代方法。
LysGH15, a phage endolysin, exhibits a particularly broad lytic spectrum againstStaphylococcus aureus, especially methicillin-resistantS. aureus(MRSA). Sequence analysis reveals that this endolysin contains a C-terminal cell wall binding domain (SH3b), which causes the endolysin to bind to host strains. In this study, the substrate binding affinity of the SH3b domain (LysGH15B) was evaluated. A fusion protein of LysGH15B and green fluorescent protein (LysGH15B–GFP) were cloned and expressed inEscherichia coli. Laser scanning confocal microscopy was used to detect the fluorescence of the treated cells irradiated at different excitation wavelengths and to determine the binding activity of LysGH15B–GFP and GFP. We found that LysGH15B–GFP not only generated green fluorescence, but, more importantly, also displayed specific affinity to staphylococcal isolates, especially MRSA. In contrast, the single GFP did not display any binding activity. The high affinity was attributed to the portion of LysGH15B and the binding activity of the fusion protein was specific to staphylococci. This study provides an insight into the SH3b domain of LysGH15. The specific binding activity may cause LysGH15B to serve as an anchoring device, and offer an alternative approach for cell surface attachment onto staphylococci.