1xi5
From Proteopedia
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Clathrin D6 coat with auxilin J-domain
Overview
Clathrin-coated pits invaginate from specific membrane compartments and, pinch off as coated vesicles. These vesicles then uncoat rapidly once, released. The Hsc70 molecular chaperone effects the uncoating reaction, and is guided to appropriate locations on clathrin lattices by the, J-domain-containing co-chaperone molecule auxilin. This raises the, question of how a local event such as ATP hydrolysis by Hsc70 can catalyse, a global disassembly. Here, we have used electron cryomicroscopy to, determine 12-A-resolution structures of in-vitro-assembled clathrin coats, in association with a carboxy-terminal fragment of auxilin that contains, both the clathrin-binding region and the J domain. We have located the, auxilin fragment by computing differences between these structures and, those lacking auxilin (described in an accompanying paper). Auxilin binds, within the clathrin lattice near contacts between an inward-projecting, C-terminal helical tripod and the crossing of two 'ankle' segments; it, also contacts the terminal domain of yet another clathrin 'leg'. It, therefore recruits Hsc70 to the neighbourhood of a set of critical, interactions. Auxilin binding produces a local change in heavy-chain, contacts, creating a detectable global distortion of the clathrin coat. We, propose a mechanism by which local destabilization of the lattice promotes, general uncoating.
About this Structure
1XI5 is a Protein complex structure of sequences from Bos taurus. Full crystallographic information is available from OCA.
Reference
Structure of an auxilin-bound clathrin coat and its implications for the mechanism of uncoating., Fotin A, Cheng Y, Grigorieff N, Walz T, Harrison SC, Kirchhausen T, Nature. 2004 Dec 2;432(7017):649-53. Epub 2004 Oct 24. PMID:15502813
Page seeded by OCA on Wed Nov 21 06:05:13 2007
