2nut: Difference between revisions
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'''Crystal Structure of the human Sec23a/24a heterodimer, complexed with the SNARE protein Sec22b''' | '''Crystal Structure of the human Sec23a/24a heterodimer, complexed with the SNARE protein Sec22b''' | ||
==Overview== | |||
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. | |||
==Disease== | ==Disease== | ||
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==About this Structure== | ==About this Structure== | ||
2NUT is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2NUT OCA]. | 2NUT is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2NUT OCA]. | ||
==Reference== | |||
The transport signal on Sec22 for packaging into COPII-coated vesicles is a conformational epitope., Mancias JD, Goldberg J, Mol Cell. 2007 May 11;26(3):403-14. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/17499046 17499046] | |||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
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[[Category: Mancias, J D.]] | [[Category: Mancias, J D.]] | ||
[[Category: Human copii sec23/24 complexed with sec22]] | [[Category: Human copii sec23/24 complexed with sec22]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | [[Category: Protein transport]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Jun 5 10:08:08 2008'' | |||
