CLONING, MOLECULAR CHARACTERIZATION, AND EXPRESSION OF THE GENES ENCODING THE LYTIC FUNCTIONS OF LACTOCOCCAL BACTERIOPHAGE-PHI-LC3 - A DUAL LYSIS SYSTEM OF MODULAR DESIGN
CLONING, MOLECULAR CHARACTERIZATION, AND EXPRESSION OF THE GENES ENCODING THE LYTIC FUNCTIONS OF LACTOCOCCAL BACTERIOPHAGE-PHI-LC3 - A DUAL LYSIS SYSTEM OF MODULAR DESIGN
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DOI：
10.1139/m94-104
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发表时间：
1994-08-01
影响因子：
2.8
通讯作者：
BIRKELAND, NK
中科院分区：
文献类型：
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作者：
BIRKELAND, NK
对编码乳酸乳球菌噬菌体phi LC 3裂解蛋白的基因进行了克隆、测序，并在大肠杆菌中表达。phi LC 3裂解基因lysA和lysB编码88个氨基酸的膜破坏蛋白（LysA）和429个氨基酸的细胞壁降解蛋白（LysB），其与来自肺炎链球菌Cp-1、Cp-7和Cp-9以及德氏噬菌体mv1的溶素具有显著的序列相似性。LysA和LysB在E.大肠杆菌的裂解率。大肠杆菌宿主细胞，并通过当克隆的lysA和lysB基因表达时对乳球菌细胞的裂解活性。LysA蛋白具有两个推定的跨膜螺旋和高度带电的N-和C-末端，并且在结构上类似于已知诱导内膜损伤的噬菌体孔蛋白，噬菌体内溶素可以通过所述内膜损伤释放到其细胞壁底物。LysB的C-末端含有两个高度同源的43个氨基酸的重复序列。LysB重复序列与其他革兰氏阳性菌、枯草芽孢杆菌噬菌体phi 29和PZA的裂解酶以及一些功能无关的蛋白质中发现的重复序列具有很强的序列相似性，它们可能参与酶与细胞壁底物的结合。双phi LC 3裂解系统的组织支持早期的建议，即模块单元的交换是蛋白质进化中的一个重要原则。
The genes encoding the lysis proteins of Lactococcus lactis bacteriophage phi LC3 were cloned, sequenced, and expressed in Escherichia coli. The phi LC3 lysis genes, lysA and lysB, encode a membrane-disrupting protein (LysA) of 88 amino acids, and a cell wall degrading protein (LysB) of 429 amino acids, which shares significant sequence similarity with lysins from the Streptococcus pneumoniae phages Cp-1, Cp-7, and Cp-9, and lactobacillus delbrueckii phage mv1. Both LysA and LysB function in E. coli, as judged by lysis of the E. coli host cells and by lytic activity against lactococcal cells when the cloned lysA and lysB genes are expressed. The LysA protein possesses two putative transmembrane helices and highly charged N- and C-termini, and is structurally similar to phage holins that are known to induce lesions in the inner membrane through which phage endolysin can be released to its cell wall substrate. The C-terminal end of LysB contains two highly homologous sequence repeats of 43 amino acids. The LysB repeats show strong sequence similarity to repeats found in lytic enzymes from other Gram-positive bacteria and from Bacillus subtilis phage phi 29 and PZA, as well as in some functionally unrelated proteins, and they are possibly involved in binding of the enzyme to the cell wall substrate. The organization of the dual phi LC3 lysis system supports earlier suggestions that exchange of modular units is an important principle in protein evolution.