The genome of S-PM2, a "photosynthetic" T4-type bacteriophage that infects marine Synechococcus strains
The genome of S-PM2, a "photosynthetic" T4-type bacteriophage that infects marine Synechococcus strains
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DOI：
10.1128/jb.187.9.3188-3200.2005
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发表时间：
2005-05-01
影响因子：
3.2
通讯作者：
Krisch, HM
中科院分区：
文献类型：
--
作者：
Mann, NH;Clokie, MRJ;Krisch, HM
噬菌体S-PM2感染了几种丰富的、生态上重要的海洋蓝细菌聚球藻。S-PM 2是一种具有等轴二十面体头部的大型裂解性噬菌体，具有可收缩的尾部，根据该标准将其归类为肌病毒（1）。S-PM 2的线性、环状排列的196，280-bp双链DNA基因组含有37.8%的G+C残基。它编码239个开放阅读框（ORF）和25个tRNA。在这些ORF中，19个编码与细胞被膜相关的蛋白，包括一个假定的S层相关蛋白。另外20个S-PM2 ORF在其蓝藻宿主的基因组中具有同源物。在编码D1蛋白的基因内存在I组自我剪接内含子。总共有40个ORF，组成离散的簇，编码参与病毒体形态发生、核苷酸代谢、基因调控和DNA复制和修复的T4蛋白的同源物。S-PM2基因组编码一些令人惊讶的大（例如，3，779个氨基酸）功能未知的ORF。我们对S-PM2基因组的分析表明，许多未知的S-PM2功能可能参与宿主细胞代谢适应噬菌体感染的要求。这一假设起源于鉴定宿主光合机构的多个噬菌体介导的修饰，这些修饰似乎对于在裂解周期期间维持能量产生至关重要。
Bacteriophage S-PM2 infects several strains of the abundant and ecologically important marine cyanobacterium Synechococcus. A large lytic phage with an isometric icosahedral head, S-PM2 has a contractile tail and by this criterion is classified as a myovirus (1). The linear, circularly permuted, 196,280-bp double-stranded DNA genome of S-PM2 contains 37.8% G+C residues. It encodes 239 open reading frames (ORFs) and 25 tRNAs. Of these ORFs, 19 appear to encode proteins associated with the cell envelope, including a putative S-layer-associated protein. Twenty additional S-PM2 ORFs have homologues in the genomes of their cyanobacterial hosts. There is a group I self-splicing intron within the gene encoding the D1 protein. A total of 40 ORFs, organized into discrete clusters, encode homologues of T4 proteins involved in virion morphogenesis, nucleotide metabolism, gene regulation, and DNA replication and repair. The S-PM2 genome encodes a few surprisingly large (e.g., 3,779 amino acids) ORFs of unknown function. Our analysis of the S-PM2 genome suggests that many of the unknown S-PM2 functions may be involved in the adaptation of the metabolism of the host cell to the requirements of phage infection. This hypothesis originates from the identification of multiple phage-mediated modifications of the host's photosynthetic apparatus that appear to be essential for maintaining energy production during the lytic cycle.