3UC9

Crystal Structure of Yeast Irc6p - A Novel Type of Conserved Clathrin Accessory Protein

Summary for 3UC9

• Entry DOI: 10.2210/pdb3uc9/pdb
• Descriptor: Increased recombination centers protein 6 (2 entities in total)
• Functional Keywords: rossmann-fold, clathrin accessory factor, recombination
• Biological source: Saccharomyces cerevisiae (Baker's yeast)
• Total number of polymer chains: 1
• Total formula weight: 27419.04

Authors

Gorynia, S.,Payne, G.S.,Cascio, D.,Sawaya, M.R. (deposition date: 2011-10-26, release date: 2012-09-12, Last modification date: 2024-02-28)

Primary citation

Gorynia, S.,Lorenz, T.C.,Costaguta, G.,Daboussi, L.,Cascio, D.,Payne, G.S.
Yeast Irc6p is a novel type of conserved clathrin coat accessory factor related to small G proteins.
Mol Biol Cell, 23:4416-4429, 2012

PubMed Abstract: Clathrin coat accessory proteins play key roles in transport mediated by clathrin-coated vesicles. Yeast Irc6p and the related mammalian p34 are putative clathrin accessory proteins that interact with clathrin adaptor complexes. We present evidence that Irc6p functions in clathrin-mediated traffic between the trans-Golgi network and endosomes, linking clathrin adaptor complex AP-1 and the Rab GTPase Ypt31p. The crystal structure of the Irc6p N-terminal domain revealed a G-protein fold most related to small G proteins of the Rab and Arf families. However, Irc6p lacks G-protein signature motifs and high-affinity GTP binding. Also, mutant Irc6p lacking candidate GTP-binding residues retained function. Mammalian p34 rescued growth defects in irc6 cells, indicating functional conservation, and modeling predicted a similar N-terminal fold in p34. Irc6p and p34 also contain functionally conserved C-terminal regions. Irc6p/p34-related proteins with the same two-part architecture are encoded in genomes of species as diverse as plants and humans. Together these results define Irc6p/p34 as a novel type of conserved clathrin accessory protein and founding members of a new G protein-like family.

PubMed: 22993212
DOI: 10.1091/mbc.E12-07-0507

Experimental method

X-RAY DIFFRACTION (1.8 Å)