A homologue of an operon required for DNA transfer in Agrobacterium is required in Brucella abortus for virulence and intracellular multiplication
A homologue of an operon required for DNA transfer in Agrobacterium is required in Brucella abortus for virulence and intracellular multiplication
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DOI：
10.1128/jb.182.17.4849-4855.2000
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发表时间：
2000-09-01
影响因子：
3.2
通讯作者：
Ugalde, RA
中科院分区：
文献类型：
--
作者：
Sieira, R;Comerci, DJ;Ugalde, RA
作为在我们实验室进行的流产布鲁氏菌2308基因组计划的一部分，我们鉴定、克隆和测序了一个基因组DNA片段，该片段含有与细菌IV型分泌系统高度同源的基因座（virB）。B。牛流产病毒B基因座由13个开放阅读框（ORF）共线排列，在virB 1和virB 2之间及ORF 12下游发现两个布鲁菌基因间区特有的简并回文重复序列。牛流产病毒virB基因座构成从virB1转录的操纵子，其在生长的稳定期被开启。A B。在HeLa细胞中，流产极性virB1突变体不能复制，表明virB操纵子在细胞内增殖中起关键作用。在virB10中引入极性和非极性突变的突变体在小鼠和HeLa细胞感染试验中表现出不同的行为，表明virB10本身对于这种类型的TV分泌装置的正确功能是必要的。小鼠感染试验表明，病毒B操纵子构成B的主要决定因素。流产毒力这表明，推定的效应分子分泌这种类型的电视分泌系统确定路由的B，流产的内质网相关的复制隔间。
As part of a Brucella abortus 2308 genome project carried out in our laboratory, we identified, cloned, and sequenced a genomic DNA fragment containing a locus (virB) highly homologous to bacterial type IV secretion systems. The B. abortus virB Locus is a collinear arrangement of 13 open reading frames (ORFs), Between virB1 and virB2 and downstream of ORF12, two degenerated, palindromic repeat sequences characteristic of Brucella intergenic regions were found. Gene reporter studies demonstrated that the B. abortus virB locus constitutes an operon transcribed from virB1 which is turned on during the stationary phase of growth. A B. abortus polar virB1 mutant failed to replicate in HeLa cells, indicating that the virB operon plays a critical role in intracellular multiplication. Mutants with polar and nonpolar mutations introduced in virB10 showed different behaviors in mice and in the HeLa cell infection assay, suggesting that virB10 per se is necessary for the correct function of this type TV secretion apparatus. Mouse infection assays demonstrated that the virB operon constitutes a major determinant of B. abortus virulence. It is suggested that putative effector molecules secreted by this type TV secretion system determine routing of B, abortus to an endoplasmic reticulum-related replication compartment.