2d3g
From Proteopedia
Double sided ubiquitin binding of Hrs-UIM
Structural highlights
Function[HGS_HUMAN] Involved in intracellular signal transduction mediated by cytokines and growth factors. When associated with STAM, it suppresses DNA signaling upon stimulation by IL-2 and GM-CSF. Could be a direct effector of PI3-kinase in vesicular pathway via early endosomes and may regulate trafficking to early and late endosomes by recruiting clathrin. May concentrate ubiquitinated receptors within clathrin-coated regions. Involved in down-regulation of receptor tyrosine kinase via multivesicular body (MVBs) when complexed with STAM (ESCRT-0 complex). The ESCRT-0 complex binds ubiquitin and acts as sorting machinery that recognizes ubiquitinated receptors and transfers them to further sequential lysosomal sorting/trafficking processes. May contribute to the efficient recruitment of SMADs to the activin receptor complex. Involved in receptor recycling via its association with the CART complex, a multiprotein complex required for efficient transferrin receptor recycling but not for EGFR degradation. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedHrs has an essential role in sorting of monoubiquitinated receptors to multivesicular bodies for lysosomal degradation, through recognition of ubiquitinated receptors by its ubiquitin-interacting motif (UIM). Here, we present the structure of a complex of Hrs-UIM and ubiquitin at 1.7-A resolution. Hrs-UIM forms a single alpha-helix, which binds two ubiquitin molecules, one on either side. These two ubiquitin molecules are related by pseudo two-fold screw symmetry along the helical axis of the UIM, corresponding to a shift by two residues on the UIM helix. Both ubiquitin molecules interact with the UIM in the same manner, using the Ile44 surface, with equal binding affinities. Mutational experiments show that both binding sites of Hrs-UIM are required for efficient degradative protein sorting. Hrs-UIM belongs to a new subclass of double-sided UIMs, in contrast to its yeast homolog Vps27p, which has two tandem single-sided UIMs. Double-sided ubiquitin binding of Hrs-UIM in endosomal protein sorting.,Hirano S, Kawasaki M, Ura H, Kato R, Raiborg C, Stenmark H, Wakatsuki S Nat Struct Mol Biol. 2006 Mar;13(3):272-7. Epub 2006 Feb 5. PMID:16462748[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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