Lysis and lysis inhibition in bacteriophage T4:: rV mutations reside in the holin t gene
Lysis and lysis inhibition in bacteriophage T4:: rV mutations reside in the holin t gene
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DOI：
10.1128/jb.181.14.4391-4396.1999
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发表时间：
1999-07-01
影响因子：
3.2
通讯作者：
Drake, JW
中科院分区：
文献类型：
--
作者：
Dressman, HK;Drake, JW
在感染易感宿主细胞群体后，T-偶联噬菌体通过从在被单个噬菌体颗粒感染后在37 ° C下约25至35分钟的裂解转换到在当游离噬菌体数量超过宿主细胞时发生的顺序感染条件下的长延迟裂解（裂解抑制）来使其产量最大化。裂解的时间取决于基因t和一个或多个快速裂解（r）基因，其失活防止裂解抑制。T编码介导T4内溶素穿过细胞内膜到达其靶细胞壁的空穴蛋白。rI蛋白已被提出用于感测重复感染，在五个相当好地表征的r基因中，只有两个，rI和rV，明显地是裂解抑制的强制性的。我们在这里表明，rV突变是等位基因，可能使t蛋白不能响应裂解抑制信号。tr等位基因聚集在t的5'三分之一处并产生强的r表型，而条件致死性t等位基因产生经典的t表型（不能裂解），其他t等位基因产生额外的、仍然知之甚少的表型。tr突变对t（+）占主导地位，这一结果表明了探测T4洞蛋白功能的特定方法。
Upon infecting populations of susceptible host cells, T-even bacteriophages maximize their yield by switching from lysis at about 25 to 35 min at 37 degrees C after infection by a single phage particle to long-delayed lysis (lysis inhibition) under conditions of sequential infection occurring when free phages outnumber host cells. The timing of lysis depends upon gene t and upon one or more rapid-lysis (r) genes whose inactivation prevents lysis inhibition. t encodes a holin that mediates the movement of the T4 endolysin though the inner cell membrane to its target, the cell wall. The rI protein has been proposed to sense superinfection, Of the five reasonably well characterized r genes, only two, rI and rV, are clearly obligatory for lysis inhibition. We show here that rV mutations are alleles oft that probably render the t protein unable to respond to the lysis inhibition signal. The tr alleles cluster in the 5' third of t and produce a strong r phenotype, whereas conditional-lethal t alleles produce the classical t phenotype (inability to lyse) and other t alleles produce additional, still poorly understood phenotypes. tr mutations are dominant to t(+), a result that suggests specific ways to probe T4 holin function.