Abstract
The flavoenzyme Ero1p produces disulfide bonds for oxidative protein folding in the endoplasmic reticulum. Disulfides generated de novo within Ero1p are transferred to protein disulfide isomerase and then to substrate proteins by dithiol-disulfide exchange reactions. Despite this key role of Ero1p, little is known about the mechanism by which this enzyme catalyzes thiol oxidation. Here, we present the X-ray crystallographic structure of Ero1p, which reveals the molecular details of the catalytic center, the role of a CXXCXXC motif, and the spatial relationship between functionally significant cysteines and the bound cofactor. Remarkably, the Ero1p active site closely resembles that of the versatile thiol oxidase module of Erv2p, a protein with no sequence homology to Ero1p. Furthermore, both Ero1p and Erv2p display essential dicysteine motifs on mobile polypeptide segments, suggesting that shuttling electrons to a rigid active site using a flexible strand is a fundamental feature of disulfide-generating flavoenzymes.
| Original language | English |
|---|---|
| Pages (from-to) | 601-610 |
| Number of pages | 10 |
| Journal | Cell |
| Volume | 117 |
| Issue number | 5 |
| DOIs | |
| State | Published - 28 May 2004 |
| Externally published | Yes |
Bibliographical note
Funding Information:We thank Harry Greenblatt for help in data backup and processing; Leah Naveh and Adam Zach for use of an oxygen electrode; Carolyn Sevier for helpful discussions; and Amnon Horovitz for critical reading of the manuscript. This work was supported by a grant from the National Institutes of General Medical Sciences to C.A.K. and from the U.S.-Israel Binational Science Foundation (to D.F. and C.A.K.). D.F. is incumbent of the Lilian and George Lyttle Career Development Chair.