Molecular Characterization and Interstrain Variability of pHPS1, a Plasmid Isolated from the Sydney Strain (SS1) ofHelicobacter pylori
Molecular Characterization and Interstrain Variability of pHPS1, a Plasmid Isolated from the Sydney Strain (SS1) ofHelicobacter pylori
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幽门螺杆菌悉尼株 (SS1) 分离质粒 pHPS1 的分子特征和株间变异
DOI：
10.1006/plas.1998.1383
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发表时间：
1999
期刊：
影响因子：
2.6
通讯作者：
Adrian K. C. Lee
中科院分区：
文献类型：
--
作者：
M. D. Ungria;T. Kolesnikow;P. Cox;Adrian K. C. Lee
克隆了幽门螺杆菌悉尼株SS1 5846bp的环状质粒PHPS1，并对其进行了序列测定和结构分析。SS1菌株被广泛用于幽门螺杆菌感染的动物研究。PHPS1的序列显示有三个开放阅读框架(ORF)，它们都是转录的。两个ORF编码假定的质粒复制蛋白REPA和RepB，类似于驻留在theta质粒上的复制酶。相反，由于序列数据库中没有与任何已知蛋白质的序列相似性，ORF2的功能仍然是神秘的。另外，用DNA斑点杂交法对57株不同临床分离的幽门螺杆菌和32株幽门螺杆菌和弯曲杆菌的这三个编码区进行了种属特异性分析。在包括SS1在内的8株幽门螺杆菌中，其编码的氨基酸序列高度保守(76-96%)。在本研究中检测到的3株幽门螺杆菌中均检出了RepB基因，其中2株仅含有RepB基因。对这两个复制酶的蛋白质序列的分析，以及先前特征的H.Pylori质粒复制蛋白，支持形成一类不同的H.Pylori质粒蛋白。此外，对幽门螺杆菌26695株、PHPS1和其他已有的幽门螺杆菌质粒序列的全基因组序列的综合分析揭示了关于幽门螺杆菌内发生质粒介导的重组的有趣见解。本研究确定了幽门螺杆菌质粒和染色体序列之间的共同区域，这些区域只能通过基因重组产生，从而提供了第一条证据，间接地证明了幽门螺杆菌质粒在产生这种重要的胃十二指肠病原体的广泛遗传异质性特征中所起的作用。
The 5846-bp circular plasmid pHPS1 of Helicobacter pylori Sydney strain, SS1, was cloned, sequenced, and structurally characterized. The SS1 strain is widely used in animal studies of H. pylori infection. The sequence of pHPS1 revealed three open reading frames (ORFs), all of which are transcribed. Two ORFs encode putative plasmid replication proteins, RepA and RepB, similar to replicases resident on theta plasmids. In contrast, the function of ORF2 remains cryptic due to the absence of sequence similarity with any known protein in sequence databases. In addition, species specificity of these three coding regions was shown using DNA dot blot hybridization in 57 diverse clinical H. pylori isolates and 32 Helicobacter and Campylobacter strains. RepA appears to be the predominant plasmid replication protein of H. pylori and the deduced amino acid sequence was highly conserved (76-96%) in 8 H. pylori isolates, including SS1. RepB was detected in 3 H. pylori isolates examined in this study, 2 of which possess only the repB gene. Analysis of the protein sequences of these two replicases, together with previously characterized H. pylori plasmid replication proteins, supports the formation of a distinct class of H. pylori plasmid proteins. Moreover, comprehensive analysis of the whole genome sequence of H. pylori strain 26695, pHPS1, and other H. pylori plasmid sequences that are available revealed interesting insights as to the occurrence of plasmid-mediated recombination within H. pylori. Common regions between plasmids and chromosome sequences of H. pylori were identified in this study which could only have arisen by genetic recombination, thus providing the first line of evidence, albeit indirectly, of the contribution of H. pylori plasmids in generating an extensive genetic heterogeneity characteristic of this important gastroduodenal pathogen.
影响因子：
14.9
作者：
AKOPYANZ, N;BUKANOV, NO;BERG, DE
通讯作者：
BERG, DE