Bacteriophage Tuc2009 encodes a tail-associated cell wall-degrading activity
Bacteriophage Tuc2009 encodes a tail-associated cell wall-degrading activity
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DOI：
10.1128/jb.186.11.3480-3491.2004
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发表时间：
2004-06-01
影响因子：
3.2
通讯作者：
van Sinderen, D
中科院分区：
文献类型：
--
作者：
Kenny, JG;McGrath, S;van Sinderen, D
Tuc2009 是有尾噬菌体超群 Siphoviridae 的 P335 型成员，最初被鉴定为革兰氏阳性细菌乳酸乳球菌 UC509 的常驻原噬菌体。位于形态发生模块内的名为 tal(2009) 的 Tuc2009 基因显示出在其编码区的 3' 部分内指定裂解活性。比较序列分析表明，Tal(2009) 的细胞壁降解部分是 M37 蛋白家族的成员，并且 Tal(2009) 缺乏细胞结合结构域，这一发现得到了结合研究的支持。 Tal (2009) 似乎在乳酸乳球菌和大肠杆菌中都经历了自介导的翻译后加工。使用针对纯化的 Tal(2009) C 端部分的抗体进行免疫电镜观察，结果显示 Tal(2009) 位于 Tuc2009 的尾尖。抗体中和研究表明，Tal(2009) 定向抗体可抑制噬菌体介导宿主裂解的能力 100 倍以上。这些数据表明tal(2009)编码参与局部细胞壁降解的尾部相关溶素，从而允许Tuc2009 DNA注射机器进入其细菌宿主的膜。
Tuc2009 is a P335-type member of the tailed-phage supergroup Siphoviridae and was originally identified as a resident prophage of the gram-positive bacterium Lactococcus lactis UC509. A Tuc2009 gene designated tal(2009) which is located within the morphogenic module was shown to specify a lytic activity within the 3' portion of its coding region. Comparative sequence analysis indicated that the cell wall-degrading part of Tal(2009) is a member of the M37 protein family and that Tal(2009) lacks a cell-binding domain, a finding supported by binding studies. Tal(2009) appears to undergo self-mediated posttranslational processing in both L. lactis and Escherichia coli. Antibodies directed against a purified C-terminal portion of Tal(2009) were used for immunoelectron microscopy, which showed that Tal(2009) is located at the tail tip of Tuc2009. Antibody neutralization studies demonstrated that Tal(2009)-directed antibodies inhibited the ability of phage to mediate host lysis by more than 100-fold. These data indicate that tal(2009) encodes a tail-associated lysin involved in localized cell wall degradation, thus allowing the Tuc2009 DNA injection machinery access to the membrane of its bacterial host.