Complete nucleotide sequence, molecular analysis and genome structure of bacteriophage A118 of Listeria monocytogenes:: implications for phage evolution
Complete nucleotide sequence, molecular analysis and genome structure of bacteriophage A118 of Listeria monocytogenes:: implications for phage evolution
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DOI：
10.1046/j.1365-2958.2000.01720.x
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发表时间：
2000-01-01
影响因子：
3.6
通讯作者：
Calendar, R
中科院分区：
文献类型：
--
作者：
Loessner, MJ;Inman, RB;Calendar, R
A118是一株从单核增生李斯特菌中分离出来的温带噬菌体，本研究报道了其40834 bp DNA的全核苷酸序列和结构分析。电镜和酶分析表明，A118基因组是一个线性的、循环排列的、末端冗余的双链DNA分子集合。没有证据表明A118病毒DNA存在内聚末端或末端酶识别位点，这表明A118病毒DNA是通过头部机制包装的。与尾轴交联的DNA部分变性图谱表明，相对于任意基因组图谱和裂解发育所需基因的方向，DNA包装是从左到右进行的。在A118基因组上鉴定出72个开放阅读框（orf），它们明显以生命周期特异性的方式组织成至少三个主要的转录单元，n端氨基酸测序、生物信息学分析和功能表征使26个orf具有可能的功能，包括DNA包装蛋白、形态蛋白、裂解组分、溶生控制相关功能和DNA重组所需的蛋白质。修改和复制。通过与其他噬菌体的基因组结构比较分析，发现A118与多种低G+C宿主细菌系统发育范围内的许多噬菌体存在局部但有时广泛的相似性，这意味着相对较近的基因或遗传模块交换。我们还在单核增生李斯特菌中鉴定了A118的附着位点attP和相应的attB。结果表明，A118整合酶对A118噬菌体的位点特异性整合发生在与枯草芽孢杆菌comK同源的宿主基因中，这是一个指定主要能力转录因子的自调节基因。
A118 is a temperate phage isolated from Listeria monocytogenes, In this study, we report the entire nucleotide sequence and structural analysis of its 40 834 bp DNA. Electron microscopic and enzymatic analyses revealed that the A118 genome is a linear, circularly permuted, terminally redundant collection of double-stranded DNA molecules. No evidence for cohesive ends or for a terminase recognition (pac) site could be obtained, suggesting that A118 viral DNA is packaged via a headful mechanism. Partial denaturation mapping of DNA cross-linked to the tail shaft indicated that DNA packaging proceeds from left to right with respect to the arbitrary genomic map and the direction of genes necessary for lytic development. Seventy-two open reading frames (ORFs) were identified on the A118 genome, which are apparently organized in a life cycle-specific manner into at least three major transcriptional units, N-terminal amino acid sequencing, bioinformatic analyses and functional characterizations enabled the assignment of possible functions to 26 ORFs, which included DNA packaging proteins, morphopoetic proteins, lysis components, lysogeny control-associated functions and proteins necessary for DNA recombination, modification and replication. Comparative analysis of the A118 genome structure with other bacteriophages revealed local, but sometimes extensive, similarities to a number of phages spanning a broader phylogenetic range of various low G+C host bacteria, which implies relatively recent exchange of genes or genetic modules, We have also identified the A118 attachment site attP and the corresponding attB in Listeria monocytogenes, and show that site-specific integration of the A118 prophage by the A118 integrase occurs into a host gene homologous to comK of Bacillus subtilis, an autoregulatory gene specifying the major competence transcription factor.