TRAPP plays a key role in the targeting and/or fusion of ER-to-Golgi transport vesicles with their acceptor compartment. TRAPP is a large multimeric protein that contains at least 10 subunits. This family contains many TRAPP family proteins. The Bet3 subunit is one of the better characterised TRAPP proteins and has a dimeric structure [2] with hydrophobic channels. The channel entrances are located on a putative membrane-interacting surface that is distinctively flat, wide and decorated with positively charged residues. Bet3 is proposed to localise TRAPP to the Golgi [2].

1: TRAPP, a highly conserved novel complex on the cis-Golgi that mediates vesicle docking and fusion. Sacher M, Jiang Y, Barrowman J, Scarpa A, Burston J, Zhang L, Schieltz D, Yates JR 3rd, Abeliovich H, Ferro-Novick S; EMBO J 1998;17:2494-2503. PMID:9564032

2: Crystal structure of bet3 reveals a novel mechanism for Golgi localization of tethering factor TRAPP. Kim YG, Sohn EJ, Seo J, Lee KJ, Lee HS, Hwang I, Whiteway M, Sacher M, Oh BH; Nat Struct Mol Biol 2005;12:38-45. PMID:15608655