Crystal structure of the endophilin-A1 BAR domain.
Endophilin has been implicated in the retrieval of membrane via endocytosis of clathrin-coated vesicles, which is crucial for the maintenance of neurotransmitter exocytosis during stimulation; both exocytosis and endocytosis are regulated by intracellular calcium levels. Here, we present the 2.3 A crystal structure of the endophilin-A1 BAR domain, which has been suggested to function in inducing and sensing membrane curvature at the site of endocytosis. Endo-BAR folds into a crescent-shaped dimer composed of two elongated, three-helix bundles. Two additional domains of 30 residues each, inserted into helix 1 at the center of the concave side of the dimer, may interfere with the proposed mode of BAR domain membrane interaction. In addition, the dimer binds 11 divalent cadmium ions in the crystal mostly with typical Ca2+ co-ordination spheres. The endophilin-1A BAR domain thus constitutes a new variant of a BAR domain, and it may link endophilin-1A BAR function to calcium regulation of endocytosis.
Weissenhorn
Winfried
W
European Molecular Biology Laboratory (EMBL), 6 rue Jules Horowitz, 38042 Grenoble, France. weissen@embl-grenoble.fr
D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry* / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid
D048868:Adaptor Proteins, Signal Transducing; C504641:endophilin A1 protein, mouse