Yoshida Mitsuhiro, Yoshida-Takashima Yukari, Nunoura Takuro, Takai Ken
Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka, Kanagawa, 237-0061, Japan,
Extremophiles. 2015 Jan;19(1):49-58. doi: 10.1007/s00792-014-0702-5. Epub 2014 Oct 30.
A temperate phage (termed AmM-1) was identified from the psychrotolerant Rhizobiales bacterium Aurantimonas sp. C5-1, which was isolated from bathypelagic water (water depth = 1,500 m) in the northwest Pacific. The AmM-1 genome is 47,800 bp in length and contains 67 coding sequences. Although phage AmM-1 morphologically belongs to the family Myoviridae, its genomic structure, particularly modular genome organization, is similar to that of lambda-type phages of Siphoviridae. Genetic and phylogenetic analyses of the structural core genes also revealed that AmM-1 has a mosaic genomic structure that includes a lambda-like head (Siphoviridae) and P2-like tail (Myoviridae). The sequences of the structural core genes of AmM-1 are distinct from those of previously characterized phage groups but similar to those of recently identified one prophage element and one phage of marine Rhizobiales bacteria: a potential prophage element in the marine psychrotolerant Aureimonas ureilytica DSM 18598 genome and the temperate phage RR-1A infecting Rhizobium radiobacter P007 isolated from deep subseafloor sediment. The mosaic genome structure of AmM-1 suggests the occurrence of genetic exchange between distinct temperate phages in marine Rhizobiales populations.
从耐冷根瘤菌目细菌橙色单胞菌属菌株C5-1中鉴定出一种温和噬菌体（命名为AmM-1），该菌株是从西北太平洋水深1500米的深海中层水体中分离得到的。AmM-1基因组长度为47,800碱基对，包含67个编码序列。尽管噬菌体AmM-1在形态上属于肌尾噬菌体科，但其基因组结构，特别是模块化基因组组织，与长尾噬菌体科的λ型噬菌体相似。对结构核心基因的遗传和系统发育分析还表明，AmM-1具有嵌合基因组结构，包括类似λ的头部（长尾噬菌体科）和类似P2的尾部（肌尾噬菌体科）。AmM-1结构核心基因的序列与先前表征的噬菌体群体不同，但与最近鉴定的一个原噬菌体元件和一个海洋根瘤菌目细菌噬菌体的序列相似：海洋耐冷解脲橙色单胞菌DSM 18598基因组中的一个潜在原噬菌体元件，以及感染从深海海底沉积物中分离的放射形根瘤菌P007的温和噬菌体RR-1A。AmM-1的嵌合基因组结构表明，海洋根瘤菌目种群中不同温和噬菌体之间发生了基因交换。
