Kanoh S, Masaki H, Yajima S, Ohta T, Uozumi T
Department of Biotechnology, Faculty of Agriculture, University of Tokyo, Japan.
Agric Biol Chem. 1991 Jun;55(6):1607-14.
Colicin E2 is encoded by the SOS-inducible colicin operon of plasmid ColE2-P9. Highly induced colicin E2 is excreted from the E. coli host cell, accompanied by quasi-lysis and cell death. These three events are all directed by the colicin lysis protein that comprises the signal peptide and a small mature lipoprotein. We constructed a mutant lysis gene encoding its complete signal peptide with addition of two external amino acids at the C-terminus. By using this mutant peptide as a reference, the wild type lysis signal peptide was identified and shown to remain quite stable after the cleavage. This mutant peptide also mimics the cleaved-off signal peptide avoiding the influence of the mature lysis lipoprotein, and suggested that cell death by the lysis protein, but neither colicin excretion nor quasi-lysis, is decided by the nature of its signal region.
大肠杆菌素E2由质粒ColE2-P9的SOS诱导型大肠杆菌素操纵子编码。高度诱导的大肠杆菌素E2从大肠杆菌宿主细胞中排出，同时伴有准裂解和细胞死亡。这三个事件均由包含信号肽和一个小的成熟脂蛋白的大肠杆菌素裂解蛋白指导。我们构建了一个突变裂解基因，该基因编码其完整的信号肽，并在C末端添加了两个外部氨基酸。以该突变肽为参照，鉴定出野生型裂解信号肽，并表明其在裂解后相当稳定。该突变肽还模拟了被切割掉的信号肽，避免了成熟裂解脂蛋白的影响，并表明裂解蛋白导致的细胞死亡，而非大肠杆菌素的排出或准裂解，是由其信号区域的性质决定的。
