This family represents the C-terminus (approximately 500 residues) of the eukaryotic coatomer alpha subunit. Coatomer (COPI) is a large cytosolic protein complex which forms a coat around vesicles budding from the Golgi apparatus. Such coatomer-coated vesicles have been proposed to play a role in many distinct steps of intracellular transport [1]. Note that many family members also contain the Pfam:PF04053 domain.

1: Coatomer (COPI)-coated vesicles: role in intracellular transport and protein sorting. Cosson P, Letourneur F; Curr Opin Cell Biol 1997;9:484-487. PMID:9261053

2: Crystal structure of alpha-COP in complex with epsilon-COP provides insight into the architecture of the COPI vesicular coat. Hsia KC, Hoelz A; Proc Natl Acad Sci U S A. 2010;107:11271-11276. PMID:20534429