Complementary Impact of Paralogous Oxa1-like Proteins of Bacillus subtilis on Post-translocational Stages in Protein Secretion*
Complementary Impact of Paralogous Oxa1-like Proteins of Bacillus subtilis on Post-translocational Stages in Protein Secretion*
复制标题
枯草芽孢杆菌旁系同源 Oxa1 样蛋白对蛋白分泌中易位后阶段的互补影响*
DOI：
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发表时间：
2003
影响因子：
4.8
通讯作者：
J. V. van Dijl
中科院分区：
文献类型：
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作者：
H. Tjalsma;S. Bron;J. V. van Dijl
在线粒体、叶绿体和革兰氏阴性真细菌中，Oxa 1 p（-like）蛋白对于膜蛋白的生物合成至关重要。在这里，我们表明，革兰氏阳性eubacteriumBacillus subtilis包含两个功能Oxa 1 p直系同源物，表示SpoIIIJ和YqjG。SpoIIIJ或YqjG的存在是细胞活力所需的。而SpoIIIJ是孢子形成所必需的，YqjG是这个发育过程所必需的。两种膜蛋白的稳定性被认为是轻微的影响后SpoIIIJ限制在YqjG的情况下。令人惊讶的是，其他膜蛋白的拓扑结构和稳定性在这些条件下保持不受影响。相反，SpoIIIJ和YqjG限制条件导致分泌蛋白稳定性的强烈后易位缺陷。总之，这些数据表明B.枯草芽孢杆菌参与膜蛋白生物合成和蛋白分泌。然而，分泌蛋白的稳定性降低似乎是SpoIIIJ/YqjG缺失的B的最突出表型。枯草杆菌细胞总之，我们的观察表明，SpoIIIJ和YqjG在B中具有不同但重叠的功能。枯草杆菌。最重要的是，Oxa 1 p蛋白家族的不同成员似乎已经获得了至少部分不同的、物种特异性的、对生命至关重要的功能。
In mitochondria, chloroplasts, and Gram-negative eubacteria, Oxa1p(-like) proteins are critical for the biogenesis of membrane proteins. Here we show that the Gram-positive eubacteriumBacillus subtilis contains two functional Oxa1p orthologues, denoted SpoIIIJ and YqjG. The presence of either SpoIIIJ or YqjG is required for cell viability. Whereas SpoIIIJ is required for sporulation, YqjG is dispensable for this developmental process. The stability of two membrane proteins was found to be mildly affected upon SpoIIIJ limitation in the absence of YqjG. Surprisingly, the topology and stability of other membrane proteins remained unaffected under these conditions. In contrast, SpoIIIJ- and YqjG-limiting conditions resulted in a strong post-translocational defect in the stability of secretory proteins. Together, these data indicate that SpoIIIJ and YqjG of B. subtilis are involved in both membrane protein biogenesis and protein secretion. However, the reduced stability of secretory proteins seems to be the most prominent phenotype of SpoIIIJ/YqjG-depleted B. subtilis cells. In conclusion, our observations show that SpoIIIJ and YqjG have different, but overlapping functions in B. subtilis. Most importantly, it seems that different members of the Oxa1p protein family have acquired at least partly distinct, species-specific, functions that are essential for life.