@article {6340,
	title = {Structure of clathrin coat with bound Hsc70 and auxilin: mechanism of Hsc70-facilitated disassembly.},
	journal = {The EMBO Journal},
	volume = {29},
	year = {2010},
	month = {2010 Feb 3},
	pages = {655-65},
	abstract = {<p>The chaperone Hsc70 drives the clathrin assembly-disassembly cycle forward by stimulating dissociation of a clathrin lattice. A J-domain containing co-chaperone, auxilin, associates with a freshly budded clathrin-coated vesicle, or with an in vitro assembled clathrin coat, and recruits Hsc70 to its specific heavy-chain-binding site. We have determined by electron cryomicroscopy (cryoEM), at about 11 A resolution, the structure of a clathrin coat (in the D6-barrel form) with specifically bound Hsc70 and auxilin. The Hsc70 binds a previously analysed site near the C-terminus of the heavy chain, with a stoichiometry of about one per three-fold vertex. Its binding is accompanied by a distortion of the clathrin lattice, detected by a change in the axial ratio of the D6 barrel. We propose that when Hsc70, recruited to a position close to its target by the auxilin J-domain, splits ATP, it clamps firmly onto its heavy-chain site and locks in place a transient fluctuation. Accumulation of the local strain thus imposed at multiple vertices can then lead to disassembly.</p>
},
	keywords = {Animals, Auxilins, Biological, Cattle, Clathrin, Clathrin-Coated Vesicles, Cryoelectron Microscopy, HSC70 Heat-Shock Proteins, Models, Molecular, Multiprotein Complexes, Protein Binding, Protein Multimerization, Protein Structure, Quaternary, Secondary},
	issn = {1460-2075},
	doi = {10.1038/emboj.2009.383},
	author = {Xing, Yi and B{\"o}cking, Till and Wolf, Matthias and Grigorieff, Nikolaus and Kirchhausen, Tomas and Harrison, Stephen C}
}
@article {6336,
	title = {Subunit interactions in bovine papillomavirus.},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {107},
	year = {2010},
	month = {2010 Apr 6},
	pages = {6298-303},
	abstract = {<p>Papillomaviruses, members of a group of dsDNA viruses associated with epithelial growths and tumors, have compact capsids assembled from 72 pentamers of the protein L1. We have determined the structure of bovine papillomavirus by electron cryomicrosopy (cryoEM), at approximately 3.6 A resolution. The density map, obtained from single-particle analysis of approximately 4,000 particle images, shows the trace of the L1 polypeptide chain and reveals how the N- and C-terminal "arms" of a subunit (extensions from its beta-jelly-roll core) associate with a neighboring pentamer. Critical contacts come from the C-terminal arm, which loops out from the core of the subunit, forms contacts (including a disulfide) with two subunits in a neighboring pentamer, and reinserts into the pentamer from which it emanates. This trace corrects one feature of an earlier model. We discuss implications of the structure for virion assembly and for pathways of infectious viral entry. We suggest that it should be possible to obtain image reconstructions of comparable resolution from cryoEM images of asymmetric particles. From the work on papillomavirus described here, we estimate that such a reconstruction will require about 1.5 million images to achieve the same number of averaged asymmetric units; structural variability will increase this number substantially.</p>
},
	keywords = {Cryoelectron Microscopy, Models, Molecular, Papillomaviridae, Protein Interaction Domains and Motifs, Protein Structure, Protein Subunits, Quaternary, Tertiary, Viral Envelope Proteins, Virion},
	issn = {1091-6490},
	doi = {10.1073/pnas.0914604107},
	author = {Wolf, Matthias and Garcea, Robert L and Grigorieff, Nikolaus and Harrison, Stephen C}
}
