期刊
JOURNAL OF MOLECULAR BIOLOGY
卷 375, 期 5, 页码 1282-1292出版社
ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
DOI: 10.1016/j.jmb.2007.11.054
关键词
YidC; oxa1; membrane protein insertion; CyoA; membrane insertase
资金
- NIGMS NIH HHS [R01 GM063862, GM63862-05, R01 GM063862-08] Funding Source: Medline
Subunit II (CyoA) of cytochrome bo(3) oxidase, which spans the inner membrane twice in bacteria, has several unusual features in membrane biogenesis. It is synthesized with an amino-terminal cleavable signal peptide. In addition, distinct pathways are used to insert the two ends of the protein. The amino-terminal domain is inserted by the YidC pathway whereas the large carboxyl-terminal domain is translocated by the SecYEG pathway. Insertion of the protein is also proton motive force (pmf)-independent. Here we examined the topogenic sequence requirements and mechanism of insertion of CyoA in bacteria. We find that both the signal peptide and the first membrane-spanning region are required for insertion of the amino-terminal periplasmic loop. The pmf-independence of insertion of the first periplasmic loop is due to the loop's neutral net charge. We observe also that the introduction of negatively charged residues into the periplasmic loop makes insertion pmf dependent, whereas the addition of positively charged residues prevents insertion unless the pmf is abolished. Insertion of the carboxyl-terminal domain in the full-length CyoA occurs by a sequential mechanism even when the CyoA amino and carboxyl-terminal domains are swapped with other domains. However, when a long spacer peptide is added to increase the distance between the amino-terminal and carboxyl-terminal domains, insertion no longer occurs by a sequential mechanism. (C) 2007 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据