7B6D

Drosophila melanogaster TRAPPCore (C1, C2, C2L, C3a/b, C4, C5, C6 subunits)

Summary for 7B6D

• Entry DOI: 10.2210/pdb7b6d/pdb
• EMDB information: 12052
• Descriptor: Trafficking protein particle complex subunit, GEO08327p1, Probable trafficking protein particle complex subunit 2, ... (7 entities in total)
• Functional Keywords: golgi, gefs, rab1, trapp, exocytosis
• Biological source: Drosophila melanogaster (Fruit fly); More
• Total number of polymer chains: 8
• Total formula weight: 159683.97

Authors

Galindo, A.,Munro, S.,Planelles-Herrero, V.J.,Degliesposti, G. (deposition date: 2020-12-07, release date: 2021-06-09, Last modification date: 2024-05-01)

Primary citation

Galindo, A.,Planelles-Herrero, V.J.,Degliesposti, G.,Munro, S.
Cryo-EM structure of metazoan TRAPPIII, the multi-subunit complex that activates the GTPase Rab1.
Embo J., 40:e107608-e107608, 2021

PubMed Abstract: The TRAPP complexes are nucleotide exchange factors that play essential roles in membrane traffic and autophagy. TRAPPII activates Rab11, and TRAPPIII activates Rab1, with the two complexes sharing a core of small subunits that affect nucleotide exchange but being distinguished by specific large subunits that are essential for activity in vivo. Crystal structures of core subunits have revealed the mechanism of Rab activation, but how the core and the large subunits assemble to form the complexes is unknown. We report a cryo-EM structure of the entire Drosophila TRAPPIII complex. The TRAPPIII-specific subunits TRAPPC8 and TRAPPC11 hold the catalytic core like a pair of tongs, with TRAPPC12 and TRAPPC13 positioned at the joint between them. TRAPPC2 and TRAPPC2L link the core to the two large arms, with the interfaces containing residues affected by disease-causing mutations. The TRAPPC8 arm is positioned such that it would contact Rab1 that is bound to the core, indicating how the arm could determine the specificity of the complex. A lower resolution structure of TRAPPII shows a similar architecture and suggests that the TRAPP complexes evolved from a single ur-TRAPP.

PubMed: 34018214
DOI: 10.15252/embj.2020107608

Experimental method

ELECTRON MICROSCOPY (4.27 Å)