Genomic characterization of lytic Staphylococcus aureus phage GH15: providing new clues to intron shift in phages
Genomic characterization of lytic Staphylococcus aureus phage GH15: providing new clues to intron shift in phages
复制标题
裂解金黄色葡萄球菌噬菌体 GH15 的基因组表征：为噬菌体内含子移位提供新线索
DOI：
10.1099/vir.0.049197-0
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发表时间：
2013-04-01
影响因子：
3.8
通讯作者：
Han, Wenyu
中科院分区：
文献类型：
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作者：
Gu, Jingmin;Liu, Xiaohe;Han, Wenyu
噬菌体GH 15是一种多价噬菌体，其显示出对多种金黄色葡萄球菌菌株的活性。这项研究分析了GH 15的基因组。GH 15的基因组大小（139806 bp）大于已知的葡萄球菌肌病毒，其G+C含量（30.23mol%）低于其它葡萄球菌肌病毒。通过质谱分析，鉴定了10种结构蛋白。分析表明，GH 15基因与GSHG 1、ISP、A5 W、Sb-1和K基因关系密切，与Twort基因关系中等。鉴于身份、覆盖率、G+C含量和基因组大小的变异性，再加上大量的嵌合体，从K到Sb-1、A5 W、ISP、G1和最终的GH 15肯定存在密切的进化关系。有趣的是，所有的内含子和内含肽存在于上述内含子中的GH 15中是不存在的，似乎有内含子丢失GH 15相比，在其他内含子中看到的内含子增益。内含子和内含肽相关基因的比较表明，在插入位点的位置之间的含内含子和无内含子的等位基因的明显区别，这可能会导致与内含子或内含肽的存在相关的共识序列的建立。GH 15基因组序列与其他病毒的比较分析不仅为葡萄球菌肌病毒的多样性提供了令人信服的证据，而且为葡萄球菌肌病毒的内含子移位提供了新的线索。
Phage GH15 is a polyvalent phage that shows activity against a wide range of Staphylcoccus aureus strains. This study analysed the genome of GH15. The genome size of GH15 (139 806 bp) was found to be larger than that of the known staphylococcal phages, and the G+C content (30.23 mol%) of GH15 was lower than that of any other staphylococcal myovirus phages. By mass spectrometry, ten structural proteins were identified. Analysis revealed that GH15 was closely related to phages G1, ISP, A5W, Sb-1 and K, and was moderately related to Twort. In light of the variability in identity, coverage, G+C content and genome size, coupled with the large number of mosaicisms, there certainly were close evolutionary relationships from K to Sb-1, A5W, ISP, G1 and finally GH15. Interestingly, all the introns and inteins present in the above phages were absent in GH15 and there appeared to be intron loss in GH15 compared with the intron gain seen in other phages. A comparison of the intron- and intein-related genes demonstrated a clear distinction in the location of the insertion site between intron-containing and intron-free alleles, and this might lead to the establishment of a consensus sequence associated with the presence of an intron or intein. The comparative analysis of the GH15 genome sequence with other phages not only provides compelling evidence for the diversity of staphylococcal myovirus phages but also offers new clues to intron shift in phages.