Clathrin self-assembly is mediated by a tandemly repeated superhelix.
Ybe, J.A., Brodsky, F.M., Hofmann, K., Lin, K., Liu, S.H., Chen, L., Earnest, T.N., Fletterick, R.J., Hwang, P.K.(1999) Nature 399: 371-375
- PubMed: 10360576
- DOI: https://doi.org/10.1038/20708
- Primary Citation of Related Structures:
1B89 - PubMed Abstract:
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.
Organizational Affiliation:
The G. W. Hooper Foundation, Department of Microbiology and Immunology, University of California San Francisco, 94143, USA.