期刊
BIOCHEMICAL SOCIETY TRANSACTIONS
卷 36, 期 -, 页码 1124-1128出版社
PORTLAND PRESS LTD
DOI: 10.1042/BST0361124
关键词
cytochrome c; DsbD; haem; thioredoxin
资金
- BBSRC (Biotechnology and Biological Sciences Research Council) [BB/E004865/1]
- EMBO (European molecular Biology organization)
- Bodossaki and A.G. Leventis Foundations
- BBSRC [BB/E004865/1] Funding Source: UKRI
- Biotechnology and Biological Sciences Research Council [BB/E004865/1, BB/C508118/1] Funding Source: researchfish
The CXXCH motif is usually recognized in the bacterial periplasm as a haem attachment site in apocytochromes c. There is evidence that the Escherichia coli Ccm (cytochrome c maturation) system recognizes little more than the CXXCH sequence. A limited number of periplasmic proteins have this motif and yet are not c-type cytochromes. To explore how unwanted haem attachment to CXXCH might be avoided, and to determine whether haem attachment to the surface of a non-cytochrome protein would be possible, we converted the active-site CXXCK motif of a thioredoxin-like protein into CXXCH, the C-terminal domain of the transmembrane oxidoreductase DsbD (cDsbD). The E. coli Ccm system was found to catalyse haem attachment to a very small percentage of the resultant protein (similar to 0.2%). We argue that cDsbD folds sufficiently rapidly that only a small fraction fails to avoid the Ccm system, in contrast with bona fide c-type cytochromes that only adopt their tertiary structure following haem attachment. We also demonstrate covalent haem attachment at a low level in vivo to the periplasmic disulfide isomerase DsbC, which contains a native CXXCH motif. These observations provide insight into substrate recognition by the Ccm system and expand our understanding of the requirements for covalent haem attachment to proteins. The possible evolutionary relationship between thioredoxins and c-type cytochromes is discussed.
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