The BioGRID | PUBLICATION VIEW

	Cell Jun (2007); 129(7):1325-36
Structure and organization of coat proteins in the COPII cage-
Fath S, Mancias JD, Bi X, Goldberg J
Howard Hughes Medical Institute and the Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA-
Abstract: COPII-coated vesicles export newly synthesized proteins from the endoplasmic reticulum- The COPII coat consists of the Sec23-24-Sar1 complex that selects cargo and the Sec13-31 assembly unit that can polymerize into an octahedral cage and deform the membrane into a bud- Crystallographic analysis of the assembly unit reveals a 28 nm long rod comprising a central alpha-solenoid dimer capped by two beta-propeller domains at each end- We construct a molecular model of the COPII cage by fitting Sec13-31 crystal structures into a recently determined electron microscopy density map- The vertex geometry involves four copies of the Sec31 beta-propeller that converge through their axial ends; there is no interdigitation of assembly units of the kind seen in clathrin cages- We also propose that the assembly unit has a central hinge-an arrangement of interlocked alpha-solenoids-about which it can bend to adapt to cages of variable curvature-
[PUBMED: 17604721]