کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2052233 | 1074224 | 2006 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: The membrane anchors of the heme chaperone CcmE and the periplasmic thioredoxin CcmG are functionally important The membrane anchors of the heme chaperone CcmE and the periplasmic thioredoxin CcmG are functionally important](/preview/png/2052233.png)
The cytochrome c maturation system of Escherichia coli contains two monotopic membrane proteins with periplasmic, functional domains, the heme chaperone CcmE and the thioredoxin CcmG. We show in a domain swap experiment that the membrane anchors of these proteins can be exchanged without drastic loss of function in cytochrome c maturation. By contrast, the soluble periplasmic forms produced with a cleavable OmpA signal sequence have low biological activity. Both the chimerical CcmE (CcmG′–′E) and the soluble periplasmic CcmE produce low levels of holo-CcmE and thus are impaired in their heme receiving capacity. Also, both forms of CcmE can be co-precipitated with CcmC, thus restricting the site of interaction of CcmE with CcmC to the C-terminal periplasmic domain. However, the low level of holo-CcmE formed in the chimera is transferred efficiently to cytochrome c, indicating that heme delivery from CcmE does not involve the membrane anchor.
Journal: FEBS Letters - Volume 580, Issue 1, 9 January 2006, Pages 216–222