Chloroplast YidC homolog Albino3 can functionally complement the bacterial YidC depletion strain and promote membrane insertion of both bacterial and chloroplast thylakoid proteins
Chloroplast YidC homolog Albino3 can functionally complement the bacterial YidC depletion strain and promote membrane insertion of both bacterial and chloroplast thylakoid proteins
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DOI：
10.1074/jbc.m110857200
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发表时间：
2002-05-31
影响因子：
4.8
通讯作者：
Dalbey, RE
中科院分区：
文献类型：
--
作者：
Jiang, FL;Yi, L;Dalbey, RE
细菌易位机制的一个新组件 YidC 已被发现，专门负责膜蛋白的整合。 YidC 与线粒体 Oxa1p 和叶绿体 Alb3 同源，它们在分别从线粒体基质和叶绿体基质插入膜蛋白的新途径中发挥作用。我们发现 Alb3 可以在功能上补充大肠杆菌 YidC 耗竭菌株，并促进 M13 原衣壳和前导肽酶的膜插入，此前已证明这些酶依赖于细菌 YidC 进行膜易位。此外，细菌中表达的叶绿体Alb3对于叶绿体cpSecE蛋白插入细菌内膜至关重要。令人惊讶的是，将 cpSecE 插入类囊体膜不需要 Alb3。这些结果强调了 Oxa1p 同源物对于细菌膜蛋白插入的重要性，并证明细菌和类囊体膜系统对 Oxa1p 同源物的需求是不同的。
A new component of the bacterial translocation machinery, YidC, has been identified that specializes in the integration of membrane proteins. YidC is homologous to the mitochondrial Oxa1p and the chloroplast Alb3, which functions in a novel pathway for the insertion of membrane proteins from the mitochondrial matrix and chloroplast stroma, respectively. We find that Alb3 can functionally complement the Escherichia coli YidC depletion strain and promote the membrane insertion of the M13 procoat and leader peptidase that were previously shown to depend on the bacterial YidC for membrane translocation. In addition, the chloroplast Alb3 that is expressed in bacteria is essential for the insertion of chloroplast cpSecE protein into the bacterial inner membrane. Surprisingly, Alb3 is not required for the insertion of cpSecE into the thylakoid membrane. These results underscore the importance of Oxa1p homologs for membrane protein insertion in bacteria and demonstrate that the requirement for Oxa1p homologs is different in the bacterial and thylakoid membrane systems.