Complete genome sequence of Rickettsia typhi and comparison with sequences of other rickettsiae
Complete genome sequence of Rickettsia typhi and comparison with sequences of other rickettsiae
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DOI：
10.1128/jb.186.17.5842-5855.2004
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发表时间：
2004-09-01
影响因子：
3.2
通讯作者：
Weinstock, GM
中科院分区：
文献类型：
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作者：
McLeod, MP;Qin, X;Weinstock, GM
伤寒立克次体是鼠斑疹伤寒的病原体，是一种专性细胞内细菌，其生命周期涉及脊椎动物和无脊椎动物宿主。在这里，我们展示了伤寒杆菌的完整基因组序列（1,111,496 bp），并将其与两个已发表的立克次体基因组序列进行比较：R. prowazekii 和 R. conorii。我们在伤寒杆菌中鉴定了 877 个基因，编码 3 个 rRNA、33 个 tRNA、3 个非编码 RNA 和 838 个蛋白质，其中 3 个是移码基因。此外，我们还发现了40多个假基因，包括整个细胞色素c氧化酶系统。三种立克次体基因组共有 775 个基因：23 个仅在普氏立克次体和伤寒立克次体中发现，15 个仅在康氏立克次体和伤寒立克次体中发现，24 个是伤寒立克次体特有的。尽管大多数基因是共线的，但与普罗瓦泽基氏菌和康诺氏伤寒菌相比，伤寒杆菌的基因顺序存在 35 kb 的倒置，该倒置接近复制末端。此外，与 R. prowazekii 和 R. conorii 相比，我们发现了 124 kb 伤寒伤寒杆菌特异性倒位，从复制起点 19 kb 开始。在未发表的西伯利亚立克次体和立氏立克次体的基因组序列中也发现了该区域的倒位，表明该区域是重排的热点。基因组比较还显示，相对于伤寒杆菌和康氏伤寒菌，普氏伤寒杆菌基因组中存在 12 kb 的插入，这似乎是在斑疹伤寒（普氏伤寒杆菌和伤寒杆菌）和斑疹热病（康氏伤寒菌）群体分化之后发生的。三向比较允许对 SpoT 分裂基因进行进一步的计算机分析，使我们提出严格的反应系统在这些立克次体中仍然发挥作用。
Rickettsia typhi, the causative agent of murine typhus, is an obligate intracellular bacterium with a life cycle involving both vertebrate and invertebrate hosts. Here we present the complete genome sequence of R. typhi (1,111,496 bp) and compare it to the two published rickettsial genome sequences: R. prowazekii and R. conorii. We identified 877 genes in R. typhi encoding 3 rRNAs, 33 tRNAs, 3 noncoding RNAs, and 838 proteins, 3 of which are frameshifts. In addition, we discovered more than 40 pseudogenes, including the entire cytochrome c oxidase system. The three rickettsial genomes share 775 genes: 23 are found only in R. prowazekii and R. typhi, 15 are found only in R. conorii and R. typhi, and 24 are unique to R. typhi. Although most of the genes are colinear, there is a 35-kb inversion in gene order, which is close to the replication terminus, in R. typhi, compared to R. prowazekii and R. conorii. In addition, we found a 124-kb R. typhi-specific inversion, starting 19 kb from the origin of replication, compared to R. prowazekii and R. conorii. Inversions in this region are also seen in the unpublished genome sequences of R. sibirica and R. rickettsii, indicating that this region is a hot spot for rearrangements. Genome comparisons also revealed a 12-kb insertion in the R. prowazekii genome, relative to R. typhi and R. conorii, which appears to have occurred after the typhus (R. prowazekii and R. typhi) and spotted fever (R. conorii) groups diverged. The three-way comparison allowed further in silico analysis of the SpoT split genes, leading us to propose that the stringent response system is still functional in these rickettsiae.