Molecular genetic analysis of the evolution of cytotoxin-converting phages and the horizontal transfer of toxin genes.

细胞毒素转化噬菌体进化和毒素基因水平转移的分子遗传学分析。

• 批准号: 09670277
• 负责人: HAYASHI Tetsuya
• 金额: $ 2.05万
• 依托单位: Shinshu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09670277/
• 关键词: bacteriophage; genome structure; molecular evolution; bacteriocin; horizontal gene transfer; toxin gene; サイトトキシン; 溶菌遺伝子; ゲノムシークエンス

φCTX is a cytotoxin-converting phage isolated from Pseudomons aeruginosa. In this study, we determined the complete nucleotide sequence of φCTX phage genome. The precise genome size was 35,538 bp. Forty seven ORFs were identified on the φCTX genome, including two previously identified genes, ctx and int. Among them, fifteen gene products were identified in the phage particle. The most striking feature of the φCTX genome was an extensive homology with the coliphage P2 and P2-related phages; more than half of the ORFs had marked homology to P2 genes. The gene arrangement on the genome was also highly conserved for the two phages, though the G+C content and codon usage of most φCTX genes were similar to those of the host P. aeruginosa chromosome. In addition, φCTX was found to share several common features with P2, including the morphology, non-inducibility, use of LPS core oligosaccharide as receptor and CaィイD22+ィエD2-dependent receptor binding. These findings indicate that φCTX is a P2-l … More ike phage well adapted to P. aeruginosa, and provide a clear evidence of the intergeneric spread and evolution of bacteriophages. Furthermore, comparative analysis of genome structures of φCTX, P2 and other P2-relatives revealed the presence of several hot spots where foreign DNAs, including the cytotoxin gene, were inserted. They appear to be deeply concerned in the acquisition of various genes that are horizontally transferred by bacteriophage infection.Pseudomonas aeruginosa produces three types of bacteriocins; R-type, F-type, and S-type pyocins. The S-type pyocin is a simple colicin-like protein, whereas the R-type resembles a contractile tail structure of bacteriophage, and the F-type a non-contractile tail of bacteriophage. Since φCTX is a member of R pyocin-related phages which are genetically and serologically related to R pyocin, above-mentioned results suggested the relatedness of R pyocin to the P2 phage family. Thus, 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 analyzed in order to elucidate the relationship between the pyocins and bacteriophages. Further, in order to specify the R2 pyocin locus, we determined the nucleotide sequence of the corresponding region of the strain PML14 which produced only F2 pyocin. The results clearly demonstrated that the R-type pyocin is derived from a common ancestral origin with the P2 phage family and the F-type from the λ phage family. 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 the both pyocins are not simple defective phages but are phage tails that have been evolutionarily specialized as bacteriocins. Less

φCTX是从铜绿假单胞菌分离的细胞毒素转化噬菌体。本研究测定了φCTX噬菌体全基因组的核苷酸序列。精确的基因组大小为35，538 bp。在φCTX基因组上共鉴定出47个ORF，其中包括ctx和int两个已知基因，在噬菌体颗粒中鉴定出15个基因产物。φCTX基因组最显著的特征是与大肠杆菌噬菌体P2和P2相关的噬菌体具有广泛的同源性;超过一半的ORF与P2基因具有显著的同源性。两株铜绿假单胞菌基因组上的基因排列也高度保守，但大多数φCTX基因的G+C含量和密码子使用与宿主铜绿假单胞菌染色体相似。此外，还发现φCTX与P2具有一些共同的特征，包括形态、非诱导性、以LPS核心寡糖作为受体以及与Ca ~（2+）D_2依赖性受体结合。这些结果表明，φCTX是一个P2- 1 ...更多信息 类似于噬菌体很好地适应铜绿假单胞菌，并提供了噬菌体属间传播和进化的明确证据。此外，对φCTX、P2和其他P2近缘种的基因组结构的比较分析揭示了几个插入外源DNA的热点，包括细胞毒素基因。铜绿假单胞菌产生三种类型的细菌素：R型、F型和S型绿脓菌素。S型绿脓菌素是一种简单的大肠杆菌素样蛋白，而R型类似于噬菌体的可收缩尾部结构，F型类似于噬菌体的非收缩尾部结构。由于φCTX是与绿脓菌素相关的噬菌体家族的一员，在遗传学和血清学上与绿脓菌素相关，上述结果表明绿脓菌素与P2噬菌体家族相关。因此，分析R2绿脓菌素基因的核苷酸序列，沿着位于铜绿假单胞菌PAO 1染色体上R2基因簇下游的F2绿脓菌素基因的核苷酸序列，以阐明绿脓菌素和噬菌体之间的关系。此外，为了确定R2绿脓菌素基因座，我们确定了仅产生F2绿脓菌素的菌株PML 14的相应区域的核苷酸序列。结果清楚地表明，R型绿脓菌素与P2噬菌体家族和来自λ噬菌体家族的F型绿脓菌素源自共同的祖先来源。这一概念得到了类似于噬菌体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，这两种绿脓菌素不是简单的缺陷型细菌，而是进化上特化为细菌素的噬菌体尾部。少

项目成果

Keisuke Nakayama: "The complete nucleotide sequencing of φctx, a cytotoxin-corverting phage of Pseudmonas aeruginouse : implzcations for phage evolution and horizontal gene transter via bacteriophages." Molecular Microbiology. 31. 399-419 (1999)

Keisuke Nakayama：“绿脓杆菌细胞毒素转化噬菌体 φctx 的完整核苷酸测序：通过噬菌体进行噬菌体进化和水平基因转移的意义”31. 399-419 (1999)。

Keisuke Nakayama: "The complete nucleotide sequence of φCTX, a cytotoxin-converting phage of Psendomonas aeruginosa : implications for phage evolution and horizontal gene transfer via bacteriophages"Molecular Microbiology. 31. 399-419 (1999)

Keisuke Nakayama：“铜绿假单胞菌的细胞毒素转化噬菌体 φCTX 的完整核苷酸序列：对噬菌体进化和通过噬菌体的水平基因转移的影响”《分子微生物学》31. 399-419 (1999)。

林 哲也: "現代医学の基礎第11巻 感染と生体防御(竹田美文、渡辺武;編) 第5章 病原細菌のゲノム解析(第11巻第5章)"岩波書店. 248(19) (2000)

Tetsuya Hayashi：“现代医学基础第 11 卷：感染和生物防御（武田义文、渡边毅编辑）第 5 章：病原菌的基因组分析（第 11 卷第 5 章）”岩波书店 248(19)（2000 年）。 ）

K. Nakayama et al.: "The complete nucleotide sequence of φCTX, a cytotoxin-converting phage of psendomonas aeruginosa implications for phage evolution and horizontal gene transfer via bacteriophages"Molecular Microbiology. 31. 399-419 (1999)

K. Nakayama 等人：“铜绿假单胞菌的细胞毒素转化噬菌体 φCTX 的完整核苷酸序列对噬菌体进化和通过噬菌体进行水平基因转移的影响”《分子微生物学》31. 399-419 (1999)。

Keisuke Nakayama: "The complete nucleotide sequence of φCTX, a cytotoxin-converting phage of Pseudomonas aerrginosa:implieations for phage enolution and horizontal gene transter via bacteriophage"Molecular Microbiology. 31. 399-419 (1999)

Keisuke Nakayama：“铜绿假单胞菌的细胞毒素转化噬菌体 φCTX 的完整核苷酸序列：通过噬菌体进行噬菌体洗脱和水平基因转移的含义”《分子微生物学》31. 399-419 (1999)。