X-ray structure of a superinfection exclusion lipoprotein from phage TP-J34 and identification of the tape measure protein as its target
X-ray structure of a superinfection exclusion lipoprotein from phage TP-J34 and identification of the tape measure protein as its target
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DOI：
10.1111/mmi.12267
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发表时间：
2013-07-01
影响因子：
3.6
通讯作者：
Heller, Knut J.
中科院分区：
文献类型：
--
作者：
Bebeacua, Cecilia;Fajardo, Juan Carlos Lorenzo;Heller, Knut J.
温带噬菌体脂蛋白是温带噬菌体溶原性模块编码的一个膜蛋白家族。温带嗜热链球菌噬菌体TP-J34的ltpTP-J34基因的表达在触发DNA释放和注射到细胞中的阶段干扰噬菌体感染。在这里，我们报告的第一个结构的重复感染排斥蛋白。我们对LtpTP-J_（34）的X射线结构进行了表征和测定。LtpTP-J34的可溶性结构域由呈现高度带负电荷的表面的三螺旋螺旋-转角-螺旋（HTH）结构域的串联组成。通过分离对LtpTP-J34敏感性降低的乳球菌噬菌体P008 wt的突变体，并通过这些突变体的基因组测序，我们获得了支持LtpTP-J34靶向噬菌体的卷尺蛋白（TMP）并阻断其插入细胞质膜的观点的证据。
Lipoproteins of temperate phage are a broad family of membrane proteins encoded in the lysogeny module of temperate phages. Expression of the ltpTP-J34 gene of temperate Streptococcus thermophilus phage TP-J34 interferes with phage infection at the stage of triggering DNA release and injection into the cell. Here, we report the first structure of a superinfection exclusion protein. We have expressed and determined the X-ray structure of LtpTP-J34. The soluble domain of LtpTP-J34 is composed of a tandem of three-helix helix-turn-helix (HTH) domains exhibiting a highly negatively charged surface. By isolating mutants of lactococcal phage P008wt with reduced sensitivities to LtpTP-J34 and by genome sequencing of such mutants we obtained evidence supporting the notion that LtpTP-J34 targets the phage's tape measure protein (TMP) and blocks its insertion into the cytoplasmic membrane.