Nakayama K, Takashima K, Ishihara H, Shinomiya T, Kageyama M, Kanaya S, Ohnishi M, Murata T, Mori H, Hayashi T
Department of Bacteriology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan.
Mol Microbiol. 2000 Oct;38(2):213-31. doi: 10.1046/j.1365-2958.2000.02135.x.
Pseudomonas aeruginosa produces three types of bacteriocins: R-, F- and S-type pyocins. The S-type pyocin is a colicin-like protein, whereas the R-type pyocin resembles a contractile but non-flexible tail structure of bacteriophage, and the F-type a flexible but non-contractile one. As genetically related phages exist for each type, these pyocins have been thought to be variations of defective phage. In the present study, the nucleotide sequence of R2 pyocin genes, along with those for F2 pyocin, which are located downstream of the R2 gene cluster on the chromosome of P. aeruginosa PAO1, was analysed in order to elucidate the relationship between the pyocins and bacteriophages. The results clearly demonstrated that the R-type pyocin is derived from a common ancestral origin with P2 phage and the F-type from lambda phage. This notion was supported by identification of a lysis gene cassette similar to those for bacteriophages. The gene organization of the R2 and F2 pyocin gene cluster, however, suggested that both pyocins are not simple defective phages, but are phage tails that have been evolutionarily specialized as bacteriocins. A systematic polymerase chain reaction (PCR) analysis of P. aeruginosa strains that produce various subtypes of R and F pyocins revealed that the genes for every subtype are located between trpE and trpG in the same or very similar gene organization as for R2 and F2 pyocins, but with alterations in genes that determine the receptor specificity.
R型、F型和S型绿脓菌素。S型绿脓菌素是一种类大肠杆菌素蛋白，而R型绿脓菌素类似于噬菌体的可收缩但不灵活的尾部结构，F型则是灵活但不可收缩的尾部结构。由于每种类型都存在遗传相关的噬菌体，这些绿脓菌素被认为是缺陷噬菌体的变体。在本研究中，分析了铜绿假单胞菌PAO1染色体上R2绿脓菌素基因以及位于R2基因簇下游的F2绿脓菌素基因的核苷酸序列，以阐明绿脓菌素与噬菌体之间的关系。结果清楚地表明，R型绿脓菌素与P2噬菌体起源相同，F型与λ噬菌体起源相同。这一观点得到了与噬菌体相似的裂解基因盒的鉴定的支持。然而，R2和F2绿脓菌素基因簇的基因组织表明，这两种绿脓菌素并非简单的缺陷噬菌体，而是在进化过程中特化为细菌素的噬菌体尾部。对产生各种R和F型绿脓菌素亚型的铜绿假单胞菌菌株进行的系统聚合酶链反应（PCR）分析表明，每种亚型的基因都位于trpE和trpG之间，其基因组织与R2和F2绿脓菌素相同或非常相似，但决定受体特异性的基因有所改变。
