Salhi Imed, Boigegrain Rose-Anne, Machold Jan, Weise Christoph, Cloeckaert Axel, Rouot Bruno
INSERM U431, Université de Montpellier 2, 34095 Montpellier Cedex 05, France.
Infect Immun. 2003 Aug;71(8):4326-32. doi: 10.1128/IAI.71.8.4326-4332.2003.
Impairment of the omp25 gene in Brucella spp. leads to attenuated strains and confers protection to the host. Omp25 and Omp31, whose functions remain unknown, were the first characterized members of group 3 outer membrane proteins (Omps) (25 to 34 kDa). Recently, genomic and proteomic approaches identified five new putative members of this family, some of which are produced in B. melitensis or B. abortus. In the present study, using protein microsequencing, we identified new members of group 3 Omps proteins produced in B. suis. Since several monoclonal antibodies (MAbs) against Omp25 cross-reacted with other members of group 3 Omps, we also performed Western immunoblotting to compare wild-type B. suis with mutants systematically having B. suis omp25-related genes knocked out. We demonstrate the production of three paralogs of Omp31 and/or Omp25 in B. suis, and the existence of a common site of signal peptide cleavage (AXAAD), which is very similar to that present in the five homologous Omps of Bartonella quintana. The seven group 3 Omps were classified in four-subgroups on the basis of percentage amino acid sequence identities: Omp25 alone, the Omp25b-Omp25c-Omp25d cluster, the Omp31/31b subgroup, and the less related Omp22 protein (also called Omp3b). Together with previous data, our results demonstrate that all new members of group 3 Omps are produced in B. suis or in other Brucella species and we propose a nomenclature that integrates all of these proteins to facilitate the understanding of future Brucella interspecies study results.
布鲁氏菌属中omp25基因的损伤会导致菌株减毒，并赋予宿主保护作用。Omp25和Omp31是3组外膜蛋白（Omps）（25至34 kDa）中最早被鉴定的成员，其功能尚不清楚。最近，基因组学和蛋白质组学方法鉴定出了该家族的五个新的假定成员，其中一些在羊种布鲁氏菌或牛种布鲁氏菌中产生。在本研究中，我们使用蛋白质微量测序技术，鉴定出了猪种布鲁氏菌中产生的3组Omps蛋白的新成员。由于几种抗Omp25的单克隆抗体（MAbs）与3组Omps的其他成员发生交叉反应，我们还进行了蛋白质免疫印迹分析，以系统地比较野生型猪种布鲁氏菌与敲除了猪种布鲁氏菌omp25相关基因的突变体。我们证明了猪种布鲁氏菌中存在Omp31和/或Omp25的三个旁系同源物，并且存在一个共同的信号肽切割位点（AXAAD），这与五日热巴尔通体的五个同源Omps中存在的位点非常相似。根据氨基酸序列同一性百分比，将这七个3组Omps分为四个亚组：单独的Omp25、Omp25b - Omp25c - Omp25d簇、Omp31/31b亚组以及相关性较低的Omp22蛋白（也称为Omp3b）。结合先前的数据，我们的结果表明，3组Omps的所有新成员均在猪种布鲁氏菌或其他布鲁氏菌物种中产生，并且我们提出了一种命名法，将所有这些蛋白质整合在一起，以促进对未来布鲁氏菌种间研究结果的理解。
