7e2c
Monomer of TRAPPII (open)
Structural highlights
FunctionTR120_YEAST Specific subunit of the TRAPP II complex, a highly conserved vesicle tethering complex that functions in the late Golgi as a guanine nucleotide exchanger (GEF) for the Golgi YPT1 GTPase. TRS120 plays a role in the YPT GEF activity of TRAPP II in concert with the two other TRAPP II-specific subunits TRS65 and TRS130.[1] [2] [3] Publication Abstract from PubMedTransport protein particle (TRAPP) complexes belong to the multiprotein tethering complex and exist in three forms-core TRAPP/TRAPPI, TRAPPII, and TRAPPIII. TRAPPII activates GTPase Ypt31/Ypt32 as the guanine nucleotide exchange factor in the trans-Golgi network to determine the maturation of Golgi cisternae into post-Golgi carriers in yeast. Here, we present cryo-EM structures of yeast TRAPPII in apo and Ypt32-bound states. All the structures show a dimeric architecture assembled by two triangle-shaped monomers, while the monomer in the apo state exhibits both open and closed conformations, and the monomer in the Ypt32-bound form only captures the closed conformation. Located in the interior of the monomer, Ypt32 binds with both core TRAPP/TRAPPI and Trs120 via its nucleotide-binding domain and binds with Trs31 via its hypervariable domain. Combined with functional analysis, the structures provide insights into the assembly of TRAPPII and the mechanism of the specific activation of Ypt31/Ypt32 by TRAPPII. Structural basis for assembly of TRAPPII complex and specific activation of GTPase Ypt31/32.,Mi C, Zhang L, Huang G, Shao G, Yang F, You X, Dong MQ, Sun S, Sui SF Sci Adv. 2022 Jan 28;8(4):eabi5603. doi: 10.1126/sciadv.abi5603. Epub 2022 Jan , 26. PMID:35080977[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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