InterPro domain: IPR006900

COPII (coat protein complex II)-coated vesicles carry proteins from the endoplasmic reticulum (ER) to the Golgi complex [ 1 ]. COPII-coated vesicles form on the ER by the stepwise recruitment of three cytosolic components: Sar1-GTP to initiate coat formation, Sec23/24 heterodimer to select SNARE and cargo molecules, and Sec13/31 to induce coat polymerisation and membrane deformation [ 2 ].

Sec23 p and Sec24p are structurally related, folding into five distinct domains: a beta-barrel, a zinc-finger ( IPR006895 ), an alpha/beta trunk domain ( IPR006896 ), an all-helical region, and a C-terminal gelsolin-like domain ( IPR007123 ). This entry describes the all-helical domain, which forms an approximately 105-residue segment with the C-terminal 30 residues. The linker between alpha-M and alpha-N contacts Sar1.

1. Structure of the Sec23p/24p and Sec13p/31p complexes of COPII. Proc. Natl. Acad. Sci. U.S.A. 98, 10704-9
2. Structure of the Sec23/24-Sar1 pre-budding complex of the COPII vesicle coat. Nature 419, 271-7