Buchrieser C, Rusniok C, Frangeul L, Couve E, Billault A, Kunst F, Carniel E, Glaser P
Laboratoire de Génomique des Microorganismes Pathogènes, Institut Pasteur, 75724 Paris Cedex 15, France.
Infect Immun. 1999 Sep;67(9):4851-61. doi: 10.1128/IAI.67.9.4851-4861.1999.
We report the complete 119,443-bp sequence of the pgm locus from Yersinia pestis and its flanking regions. Sequence analysis confirms that the 102-kb unstable pgm locus is composed of two distinct parts: the pigmentation segment and a high-pathogenicity island (HPI) which carries virulence genes involved in iron acquisition (yersiniabactin biosynthetic gene cluster). Within the HPI, three genes coding for proteins related to phage proteins were uncovered. They are located at both extremities indicating that the entire HPI was acquired en bloc by phage-mediated horizontal transfer. We identified, within the pigmentation segment, two novel loci that may be involved in virulence: a fimbriae gene cluster and a locus probably encoding a two component regulatory system similar to the BvgAS regulatory system of Bordetella pertussis. Three genes containing frameshift mutations and two genes interrupted by insertion element insertion were found within this region. To investigate diversity among different Y. pestis and Yersinia pseudotuberculosis strains, the sequence of selected regions of the pgm locus and flanking regions were compared from 20 different Y. pestis and 10 Y. pseudotuberculosis strains. The results showed that the genes interrupted in Y. pestis are intact in Y. pseudotuberculosis. However, one of these mutations, in the bvgS homologue, is only present in Y. pestis strains of biovar Orientalis and not in those of the biovars Antiqua and Medievalis. The results obtained by analysis of variable positions in the sequence are in accordance with historical records, confirming that biovar Orientalis is the most recent lineage. Furthermore, sequence comparisons among 29 Yersinia strains suggest that Y. pestis is a recently emerged pathogen that is probably entering the initial phase of reductive evolution.
我们报道了来自鼠疫耶尔森菌的pgm基因座及其侧翼区域完整的119,443碱基对序列。序列分析证实，这个102千碱基对的不稳定pgm基因座由两个不同部分组成：色素沉着区段和一个携带与铁摄取相关毒力基因（yersiniabactin生物合成基因簇）的高致病性岛（HPI）。在HPI内，发现了三个编码与噬菌体蛋白相关蛋白质的基因。它们位于两端，表明整个HPI是通过噬菌体介导的水平转移整体获得的。我们在色素沉着区段内鉴定出两个可能与毒力有关的新基因座：一个菌毛基因簇和一个可能编码类似于百日咳博德特氏菌BvgAS调节系统的双组分调节系统的基因座。在该区域内发现了三个含有移码突变的基因和两个被插入元件插入打断的基因。为了研究不同鼠疫耶尔森菌和假结核耶尔森菌菌株之间的差异，比较了来自20株不同鼠疫耶尔森菌和10株假结核耶尔森菌菌株的pgm基因座及侧翼区域选定区域的序列。结果显示，在鼠疫耶尔森菌中中断的基因在假结核耶尔森菌中是完整的。然而，这些突变之一，即在bvgS同源物中的突变，仅存在于东方生物变种的鼠疫耶尔森菌菌株中，而不存在于古典型和中世纪型生物变种的菌株中。通过分析序列中可变位置获得的结果与历史记录一致，证实东方生物变种是最新的谱系。此外，29株耶尔森菌菌株之间的序列比较表明，鼠疫耶尔森菌是一种最近出现的病原体，可能正在进入简化进化的初始阶段。
