Potential Role of the Host-Derived Cell-Wall Binding Domain of Endolysin CD16/50L as a Molecular Anchor in Preservation of Uninfected Clostridioides difficile for New Rounds of Phage Infection.
Potential Role of the Host-Derived Cell-Wall Binding Domain of Endolysin CD16/50L as a Molecular Anchor in Preservation of Uninfected Clostridioides difficile for New Rounds of Phage Infection.
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DOI：
10.1128/spectrum.02361-21
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发表时间：
2022-04-27
影响因子：
3.7
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中科院分区：
文献类型：
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内溶素是噬菌体编码的细胞壁水解酶，其降解细菌细胞壁的肽聚糖层。该酶通常在噬菌体裂解周期的晚期表达，并且是后代逃逸所需的。感染革兰氏阳性菌的噬菌体的内溶素通常包含两个结构域：肽聚糖水解酶和细胞壁结合结构域（CBD）。虽然内溶素的催化结构域是相对充分的研究，CBD的确切作用是模糊的，仍然存在争议。在这里，我们专注于从最近分离的艰难梭菌噬菌体的内溶素CBD的功能。我们发现，CBD不是裂解活性所必需的，这是由C的表面层强烈阻止的。很难有趣的是，隐马尔可夫模型分析表明，内溶素CBD可能来源于C.艰难的细胞壁蛋白质，但具有较高的结合亲和力，细菌细胞壁多糖。此外，CBD形成同二聚体，其形成是与表面活性剂相互作用所必需的。重要的是，内溶素扩散和连续的细胞溶解试验表明，内溶素的CBD是酶锚定到溶解后细胞壁残余物所必需的，这表明它在限制酶扩散、保护邻近宿主细胞方面的生理作用，从而使噬菌体后代能够启动新一轮感染。总之，这项研究提供了通过CBD调节内溶素的见解，并可能应用于内溶素治疗C。艰难感染重要性内溶素是在噬菌体基因组中编码的肽聚糖水解酶。该酶由于其作为抗菌处理的潜在用途而具有吸引力。为了将内溶素用于治疗，了解内溶素的基本作用变得重要。本文研究了一种大肠杆菌内溶素的细胞壁结合域（CBD）的功能。艰难噬菌体该结构域与细菌细胞壁蛋白的细胞壁相关模块同源，可能是在噬菌体-宿主共同进化过程中获得的。CBD与细菌细胞壁的相互作用减少了酶扩散，从而限制了邻近细菌的细胞裂解。我们的研究结果表明，内溶素被困的细胞壁残留物通过CBD，并可能作为一个优势噬菌体复制。因此，采用CBD-少的内溶素可能是使用内溶素治疗C.艰难感染
Endolysin is a phage-encoded cell-wall hydrolase which degrades the peptidoglycan layer of the bacterial cell wall. The enzyme is often expressed at the late stage of the phage lytic cycle and is required for progeny escape. Endolysins of bacteriophage that infect Gram-positive bacteria often comprises two domains: a peptidoglycan hydrolase and a cell-wall binding domain (CBD). Although the catalytic domain of endolysin is relatively well-studied, the precise role of CBD is ambiguous and remains controversial. Here, we focus on the function of endolysin CBD from a recently isolated Clostridioides difficile phage. We found that the CBD is not required for lytic activity, which is strongly prevented by the surface layer of C. difficile. Intriguingly, hidden Markov model analysis suggested that the endolysin CBD is likely derived from the CWB2 motif of C. difficile cell-wall proteins but possesses a higher binding affinity to bacterial cell-wall polysaccharides. Moreover, the CBD forms a homodimer, formation of which is necessary for interaction with the surface saccharides. Importantly, endolysin diffusion and sequential cytolytic assays showed that CBD of endolysin is required for the enzyme to be anchored to post-lytic cell-wall remnants, suggesting its physiological roles in limiting diffusion of the enzyme, preserving neighboring host cells, and thereby enabling the phage progeny to initiate new rounds of infection. Taken together, this study provides an insight into regulation of endolysin through CBD and can potentially be applied for endolysin treatment against C. difficile infection. IMPORTANCE Endolysin is a peptidoglycan hydrolase encoded in a phage genome. The enzyme is attractive due to its potential use as antibacterial treatment. To utilize endolysin for the therapeutic propose, understanding of the fundamental role of endolysin becomes important. Here, we investigate the function of cell-wall binding domain (CBD) of an endolysin from a C. difficile phage. The domain is homologous to a cell-wall associating module of bacterial cell-wall proteins, likely acquired during phage-host coevolution. The interaction of CBD to bacterial cell walls reduces enzyme diffusion and thereby limits cell lysis of the neighboring bacteria. Our findings indicate that the endolysin is trapped to the cell-wall residuals through CBD and might serve as an advantage for phage replication. Thus, employing a CBD-less endolysin might be a feasible strategy for using endolysin for the treatment of C. difficile infection.
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影响因子：
14.9
作者：
Blum M;Chang HY;Chuguransky S;Grego T;Kandasaamy S;Mitchell A;Nuka G;Paysan-Lafosse T;Qureshi M;Raj S;Richardson L;Salazar GA;Williams L;Bork P;Bridge A;Gough J;Haft DH;Letunic I;Marchler-Bauer A;Mi H;Natale DA;Necci M;Orengo CA;Pandurangan AP;Rivoire C;Sigrist CJA;Sillitoe I;Thanki N;Thomas PD;Tosatto SCE;Wu CH;Bateman A;Finn RD
通讯作者：
Finn RD
影响因子：
3.7
作者：
Finn E;Andersson FL;Madin-Warburton M
通讯作者：
Madin-Warburton M
影响因子：
4.3
作者：
Bern, Marshall;Beniston, Richard;Mesnage, Stephane
通讯作者：
Mesnage, Stephane
影响因子：
6.7
作者：
Dunne M;Mertens HD;Garefalaki V;Jeffries CM;Thompson A;Lemke EA;Svergun DI;Mayer MJ;Narbad A;Meijers R
通讯作者：
Meijers R
影响因子：
6.7
作者：
Chu, Michele;Mallozzi, Michael J. G.;Vedantam, Gayatri
通讯作者：
Vedantam, Gayatri