Sano Y, Matsui H, Kobayashi M, Kageyama M
Mitsubishi Kasei Institute of Life Sciences, Tokyo, Japan.
J Bacteriol. 1993 May;175(10):2907-16. doi: 10.1128/jb.175.10.2907-2916.1993.
Pyocins S1 and S2 are S-type bacteriocins of Pseudomonas aeruginosa with different receptor recognition specificities. The genetic determinants of these pyocins have been cloned from the chromosomes of P. aeruginosa NIH-H and PAO, respectively. Each determinant constitutes an operon encoding two proteins of molecular weights 65,600 and 10,000 (pyocin S1) or 74,000 and 10,000 (pyocin S2) with a characteristic sequence (P box), a possible regulatory element involved in the induction of pyocin production, in the 5' upstream region. These pyocins have almost identical primary sequences; only the amino-terminal portions of the large proteins are substantially different. The sequence homology suggests that pyocins S1 and S2, like pyocin AP41, originated from a common ancestor of the E2 group colicins. Purified pyocins S1 and S2 make up a complex of the two proteins. Both pyocins cause breakdown of chromosomal DNA as well as complete inhibition of lipid synthesis in sensitive cells. The large protein, but not the pyocin complex, shows in vitro DNase activity. This activity is inhibited by the small protein of either pyocin. Putative domain structures of these pyocins and their killing mechanism are discussed.
绿脓菌素S1和S2是铜绿假单胞菌的S型细菌素,具有不同的受体识别特异性。这些绿脓菌素的遗传决定因素已分别从铜绿假单胞菌NIH-H和PAO的染色体中克隆出来。每个决定因素构成一个操纵子,编码分子量为65,600和10,000的两种蛋白质(绿脓菌素S1)或74,000和10,000的两种蛋白质(绿脓菌素S2),在5'上游区域具有一个特征序列(P盒),这是一个可能参与诱导绿脓菌素产生的调控元件。这些绿脓菌素具有几乎相同的一级序列;只有大蛋白质的氨基末端部分有很大差异。序列同源性表明,绿脓菌素S1和S2与绿脓菌素AP41一样,起源于E2组大肠杆菌素的共同祖先。纯化的绿脓菌素S1和S2构成了这两种蛋白质的复合物。两种绿脓菌素都会导致敏感细胞中的染色体DNA断裂以及脂质合成的完全抑制。大蛋白质而非绿脓菌素复合物在体外显示出DNase活性。这种活性受到任何一种绿脓菌素的小蛋白质的抑制。讨论了这些绿脓菌素的推定结构域结构及其杀伤机制。