title: Molecular model for a complete clathrin lattice from electron cryomicroscopy.
abstract: Clathrin-coated vesicles are important vehicles of membrane traffic in cells. We report the structure of a clathrin lattice at subnanometre resolution, obtained from electron cryomicroscopy of coats assembled in vitro. We trace most of the 1,675-residue clathrin heavy chain by fitting known crystal structures of two segments, and homology models of the rest, into the electron microscopy density map. We also define the position of the central helical segment of the light chain. A helical tripod, the carboxy-terminal parts of three heavy chains, projects inward from the vertex of each three-legged clathrin triskelion, linking that vertex to 'ankles' of triskelions centred two vertices away. Analysis of coats with distinct diameters shows an invariant pattern of contacts in the neighbourhood of each vertex, with more variable interactions along the extended parts of the triskelion 'legs'. These invariant local interactions appear to stabilize the lattice, allowing assembly and uncoating to be controlled by events at a few specific sites.
authors.affiliation: Biophysics Graduate Program, Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Fotin
authors.forename: Yifan
authors.initials: Y
authors.lastname: Cheng
authors.forename: Piotr
authors.initials: P
authors.lastname: Sliz
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Grigorieff
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Harrison
authors.forename: Tomas
authors.initials: T
authors.lastname: Kirchhausen
authors.forename: Thomas
authors.initials: T
authors.lastname: Walz
mesh_terms: D000818:Animals; D002417:Cattle; D002966:Clathrin / Q000737:chemistry* / Q000648:ultrastructure*; D020285:Cryoelectron Microscopy; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D020836:Protein Structure, Quaternary
chemical_list: D002966:Clathrin