Journal
NATURE STRUCTURAL & MOLECULAR BIOLOGY
Volume 26, Issue 8, Pages 704-+Publisher
NATURE PUBLISHING GROUP
DOI: 10.1038/s41594-019-0262-6
Keywords
-
Funding
- U.S. National Institutes of Health [R01 CA231466]
- Michigan Economic Development Corporation
- Michigan Technology Tri-Corridor [085P1000817]
Ask authors/readers for more resources
In eukaryotes, a nascent peptide entering the endoplasmic reticulum (ER) is scanned by two Sec61 translocon-associated large membrane machines for protein N-glycosylation and protein O-mannosylation, respectively. While the structure of the eight-protein oligosaccharyltransferase complex has been determined recently, the structures of mannosyltransferases of the PMT family, which are an integral part of ER protein homeostasis, are still unknown. Here we report cryo-EM structures of the Saccharomyces cerevisiae Pmt1-Pmt2 complex bound to a donor and an acceptor peptide at 3.2-angstrom resolution, showing that each subunit contains 11 transmembrane helices and a lumenal beta-trefoil fold termed the MIR domain. The structures reveal the substrate recognition model and confirm an inverting mannosyl-transferring reaction mechanism by the enzyme complex. Furthermore, we found that the transmembrane domains of Pmt1 and Pmt2 share a structural fold with the catalytic subunits of oligosaccharyltransferases, confirming a previously proposed evolutionary relationship between protein O-mannosylation and protein N-glycosylation.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available