The terminally redundant, nonpermuted genome of Listeria bacteriophage A511:: a model for the SPO1-like myoviruses of gram-positive bacteria
The terminally redundant, nonpermuted genome of Listeria bacteriophage A511:: a model for the SPO1-like myoviruses of gram-positive bacteria
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DOI：
10.1128/jb.00461-08
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发表时间：
2008-09-01
影响因子：
3.2
通讯作者：
Loessner, Martin J.
中科院分区：
文献类型：
--
作者：
Klumpp, Jochen;Dorscht, Julia;Loessner, Martin J.
关于一类特殊的肌病毒，即感染低G + C含量的革兰氏阳性宿主细菌（厚壁菌门）的SPO 1样噬菌体的信息很少。我们目前的基因组分析和分子特性的大型，毒性，广泛的宿主范围李斯特菌噬菌体A511。A511含有134，494 bp的单位（信息）基因组，包括190个推定的开放阅读框架（ORF）和16个tRNA基因，以尾状病毒目中常见的模块化方式组织。电子显微镜、酶促片段化分析和测序显示，A511 DNA分子含有总共3，125 bp的线性末端重复序列，包括9个小的推定ORF。这种特殊的基因组结构解释了为什么A511不能进行一般转导。A511与李斯特菌噬菌体P100和其他形态学相关的感染厚壁菌门的细菌如葡萄球菌噬菌体K和乳杆菌噬菌体LP 65具有显著的序列同源性。同样的，但更广泛的末端重复也存在于EMP 100（类似于6 kb）和K（类似于20 kb）。高分辨率电子显微镜首次揭示了这些病毒中存在六重对称的长尾纤维。基于质谱的肽指纹图谱允许分配单个蛋白质的A511结构组分。根据A511及其亲缘菌的数据，我们认为SPO 1样肌病毒的特征在于：（i）感染革兰氏阳性、低G + C含量的细菌;（ii）在宿主菌属内具有广泛的宿主范围和严格的毒性生活方式;（iii）相似的形态、序列相关性和噬菌体基因组结构的共线性;（iv）与其他病毒的相似性。和（iv）大的双链DNA基因组，具有不同大小的非排列末端重复序列。
Only little information on a particular class of myoviruses, the SPO1-like bacteriophages infecting low-G+C-content, gram-positive host bacteria (Firmicutes), is available. We present the genome analysis and molecular characterization of the large, virulent, broad-host-range Listeria phage A511. A511 contains a unit (informational) genome of 134,494 bp, encompassing 190 putative open reading frames (ORFs) and 16 tRNA genes, organized in a modular fashion common among the Caudovirales. Electron microscopy, enzymatic fragmentation analyses, and sequencing revealed that the A511 DNA molecule contains linear terminal repeats of a total of 3,125 bp, encompassing nine small putative ORFs. This particular genome structure explains why A511 is unable to perform general transduction. A511 features significant sequence homologies to Listeria phage P100 and other morphologically related phages infecting Firmicutes such as Staphylococcus phage K and Lactobacillus phage LP65. Equivalent but more-extensive terminal repeats also exist in phages P100 (similar to 6 kb) and K (similar to 20 kb). High-resolution electron microscopy revealed, for the first time, the presence of long tail fibers organized in a sixfold symmetry in these viruses. Mass spectrometry-based peptide fingerprinting permitted assignment of individual proteins to A511 structural components. On the basis of the data available for A511 and relatives, we propose that SPO1-like myoviruses are characterized by (i) their infection of gram-positive, low-G+C-content bacteria; (ii) a wide host range within the host bacterial genus and a strictly virulent lifestyle; (iii) similar morphology, sequence relatedness, and collinearity of the phage genome organization; and (iv) large double-stranded DNA genomes featuring nonpermuted terminal repeats of various sizes.