Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Vilnius University, Vilnius, Lithuania.
PLoS One. 2013 Apr 9;8(4):e60717. doi: 10.1371/journal.pone.0060717. Print 2013.
At 346 kbp in size, the genome of a jumbo bacteriophage vB_KleM-RaK2 (RaK2) is the largest Klebsiella infecting myovirus genome sequenced to date. In total, 272 out of 534 RaK2 ORFs lack detectable database homologues. Based on the similarity to biologically defined proteins and/or MS/MS analysis, 117 of RaK2 ORFs were given a functional annotation, including 28 RaK2 ORFs coding for structural proteins that have no reliable homologues to annotated structural proteins in other organisms. The electron micrographs revealed elaborate spike-like structures on the tail fibers of Rak2, suggesting that this phage is an atypical myovirus. While head and tail proteins of RaK2 are mostly myoviridae-related, the bioinformatics analysis indicate that tail fibers/spikes of this phage are formed from podovirus-like peptides predominantly. Overall, these results provide evidence that bacteriophage RaK2 differs profoundly from previously studied viruses of the Myoviridae family.
大小为 346 kbp，巨型噬菌体 vB_KleM-RaK2（RaK2）的基因组是迄今为止测序的最大的感染肺炎克雷伯氏菌的肌病毒基因组。总共，RaK2 的 534 个 ORF 中有 272 个缺乏可检测到的数据库同源物。基于与生物学定义的蛋白质的相似性和/或 MS/MS 分析，RaK2 的 117 个 ORF 被赋予了功能注释，其中包括 28 个 RaK2 ORF 编码结构蛋白，这些蛋白与其他生物中注释的结构蛋白没有可靠的同源物。电子显微镜显示，RaK2 的尾纤维上有精细的刺状结构，表明该噬菌体是一种非典型的肌病毒。虽然 RaK2 的头部和尾部蛋白主要与肌病毒科相关，但生物信息学分析表明，该噬菌体的尾纤维/刺由类似于痘病毒的肽组成。总的来说，这些结果表明噬菌体 RaK2 与先前研究的肌病毒科病毒有很大的不同。
