Authors: | Mancias, J. D.; Goldberg, J. |
Article Title: | The transport signal on sec22 for packaging into COPII-coated vesicles is a conformational epitope |
Abstract: | The mechanism of cargo concentration into ER-derived vesicles involves interactions between the COPII vesicular coat complex and cargo transport signals-peptide sequences of 10-15 residues. The SNARE protein Sec22 contains a signal that binds the COPII subcomplex Sec23/24 and specifies its endoplasmic reticulum (ER) exit as an unassembled SNARE. The 200 kDa crystal structure of Sec22 bound to Sec23/24 reveals that the transport signal is a folded epitope rather than a conventional short peptide sequence. The NIE segment of the SNARE motif folds against the N-terminal longin domain, and this closed form of Sec22 binds at the Sec23/24 interface. Thus, COPII recognizes unassembled Sec22 via a folded epitope, whereas Sec22 assembly into SNARE complexes would mask the NIE segment. The concept of a conformational epitope as a transport signal suggests packaging mechanisms in which a coat is sensitive to the folded state of a cargo protein or the assembled state of a multiprotein complex. © 2007 Elsevier Inc. All rights reserved. |
Keywords: | controlled study; human cell; nonhuman; protein conformation; proteins; animals; complex formation; models, biological; protein binding; endoplasmic reticulum; amino acid sequence; molecular sequence data; amino terminal sequence; recombinant fusion proteins; cell culture; nucleotide sequence; carrier proteins; epitope; protein transport; cellbio; crystal structure; computer simulation; crystallography, x-ray; multiprotein complexes; chemical structure; conformational transition; conformation; protein folding; protein structure; signal processing; biological transport; epitopes; vesicular transport proteins; coat protein complex ii; coated vesicle; cop-coated vesicles; membrane transport proteins; snare protein; protein sorting signals; r-snare proteins; snare proteins |
Journal Title: | Molecular Cell |
Volume: | 26 |
Issue: | 3 |
ISSN: | 1097-2765 |
Publisher: | Cell Press |
Date Published: | 2007-01-01 |
Start Page: | 403 |
End Page: | 414 |
Language: | English |
DOI: | 10.1016/j.molcel.2007.03.017 |
PUBMED: | 17499046 |
PROVIDER: | scopus |
DOI/URL: | |
Notes: | --- - "Cited By (since 1996): 41" - "Export Date: 17 November 2011" - "CODEN: MOCEF" - "Molecular Sequence Numbers: GENBANK: CAA21224, CAA92988, CAB58402, EAQ92206, NP_006314, NP_013370, NP_014349, NP_068817, NP_172653, NP_189008, NP_610531, NP_730979, P15303, Q15436, Q15437, XP_394884, XP_503201, XP_646421, XP_720881, XP_784354, XP_795453, XP_823008, XP_960888, XP_961404, XP_975087, AAC39893, AAS51681, AAW26504, ABF18345, BAE61887;" - "Source: Scopus" |