P2 growth restriction on an rpoC mutant is suppressed by alleles of the Rz1 homolog lysC
P2 growth restriction on an rpoC mutant is suppressed by alleles of the Rz1 homolog lysC
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DOI：
10.1128/jb.186.14.4628-4637.2004
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发表时间：
2004-07-01
影响因子：
3.2
通讯作者：
Severinov, K
中科院分区：
文献类型：
--
作者：
Markov, D;Christie, GE;Severinov, K
大肠杆菌菌株397 c携带温度敏感性突变rpoC 397，该突变去除了RNA聚合酶β '亚基的最后50个氨基酸，并且不允许噬菌体P2铺板。P2戈尔突变体生产性感染397 c，并定义了一个新的基因，lysC，由广泛重叠的P2裂解辅助基因，lysB的阅读框架编码。lysC相对于lysB的不寻常位置让人想起λ噬菌体的Rz/Rz 1裂解基因对。事实上，lysB和lysC的共表达补充了X Rz/Rz 1无效突变体的生长缺陷，表明LysB/C对在基因排列和功能上与Rz/Rz 1相似。携带rpoC 397突变的细胞表现出P2诱导的裂解的早期发作，其被lysC中的戈尔突变抑制。我们提出，由rpoC 397突变引起的宿主基因表达的变化导致细菌细胞壁组成的变化，使细胞更容易受到P2介导的裂解，并防止后代噬菌体的积累足以形成噬菌斑。
Escherichia coli strain 397c carries a temperature-sensitive mutation, rpoC397, that removes the last 50 amino acids of the RNA polymerase beta' subunit and is nonpermissive for plating of bacteriophage P2. P2 gor mutants productively infect 397c and define a new gene, lysC, encoded by a reading frame that extensively overlaps the P2 lysis accessory gene, lysB. The unusual location of lysC with respect to lysB is reminiscent of the Rz/Rz1 lysis gene pair of phage lambda. Indeed, coexpression of lysB and lysC complemented the growth defect of X Rz/Rz1 null mutants, indicating that the LysB/C pair is similar to Rz/Rz1 in both gene arrangement and function. Cells carrying the rpoC397 mutation exhibited an early onset of P2-induced lysis, which was suppressed by the gor mutation in lysC. We propose that changes in host gene expression resulting from the rpoC397 mutation result in changes in the composition of the bacterial cell wall, making the cell more susceptible to P2-mediated lysis and preventing accumulation of progeny phage sufficient for plaque formation.