1b89

Publication Abstract from PubMed

Clathrin is a triskelion-shaped cytoplasmic protein that polymerizes into a polyhedral lattice on intracellular membranes to form protein-coated membrane vesicles. Lattice formation induces the sorting of membrane proteins during endocytosis and organelle biogenesis by interacting with membrane-associated adaptor molecules. The clathrin triskelion is a trimer of heavy-chain subunits (1,675 residues), each binding a single light-chain subunit, in the hub domain (residues 1,074-1,675). Light chains negatively modulate polymerization so that intracellular clathrin assembly is adaptor-dependent. Here we report the atomic structure, to 2.6 A resolution, of hub residues 1,210-1,516 involved in mediating spontaneous clathrin heavy-chain polymerization and light-chain association. The hub fragment folds into an elongated coil of alpha-helices, and alignment analyses reveal a 145-residue motif that is repeated seven times along the filamentous leg and appears in other proteins involved in vacuolar protein sorting. The resulting model provides a three-dimensional framework for understanding clathrin heavy-chain self-assembly, light-chain binding and trimerization.

Clathrin self-assembly is mediated by a tandemly repeated superhelix.,Ybe JA, Brodsky FM, Hofmann K, Lin K, Liu SH, Chen L, Earnest TN, Fletterick RJ, Hwang PK Nature. 1999 May 27;399(6734):371-5. PMID:10360576^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.