1yx6
From Proteopedia
Solution Structure of S5a UIM-2/Ubiquitin Complex
Structural highlights
Function[PSD4_HUMAN] Guanine nucleotide exchange factor for ARF6 and ARL14/ARF7. Through ARL14 activation, controls the movement of MHC class II-containing vesicles along the actin cytoskeleton in dendritic cells. Involved in membrane recycling. Interacts with several phosphatidylinositol phosphate species, including phosphatidylinositol 3,4-bisphosphate, phosphatidylinositol 3,5-bisphosphate and phosphatidylinositol 4,5-bisphosphate.[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedUbiquitin is a key regulatory molecule in diverse cellular events. How cells determine the outcome of ubiquitylation remains unclear; however, a likely determinant is the specificity of ubiquitin receptor proteins for polyubiquitin chains of certain length and linkage. Proteasome subunit S5a contains two ubiquitin-interacting motifs (UIMs) through which it recruits ubiquitylated substrates to the proteasome for their degradation. Here, we report the structure of S5a (196-306) alone and complexed with two monoubiquitin molecules. This construct contains the two UIMs of S5a and we reveal their different ubiquitin-binding mechanisms and provide a rationale for their unique specificities for different ubiquitin-like domains. Furthermore, we provide direct evidence that S5a (196-306) binds either K63-linked or K48-linked polyubiquitin, and in both cases prefers longer chains. On the basis of these results we present a model for how S5a and other ubiquitin-binding proteins recognize polyubiquitin. Structure of S5a bound to monoubiquitin provides a model for polyubiquitin recognition.,Wang Q, Young P, Walters KJ J Mol Biol. 2005 May 6;348(3):727-39. PMID:15826667[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Human | Large Structures | Walters, K J | Wang, Q | Young, P | Hydrolase | Polyubiquitin | Proteasome | S5a | Uim
