This entry includes the Conserved oligomeric Golgi complex subunit 3 (COG3, also known as Sec34) which is a component of the peripheral membrane COG complex, involved in intra-Golgi protein trafficking. COG is a member of the complexes associated with tethering containing helical rods (CATCHR) family which also includes the exocyst, GARP and DSL1 complexes, which are evolutionarily related and share structural features consisting of alpha-helical bundles towards the C-terminal and an N-terminal coiled-coil region.