3dm7
Crystal Structure of the Vps75 Histone Chaperone
Structural highlights
FunctionVPS75_YEAST Histone chaperone which acts as a cofactor stimulating the histone H3 'Lys-56' acetylation by RTT109. May be involved in vacuolar proteins sorting.[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 PubMedThe vacuolar protein sorting 75 (Vps75) histone chaperone participates in chromatin assembly and disassembly at both active and inactive genes through the preferential binding to histone H3-H4. Vps75 is also one of two histone chaperones, along with antisilencing factor 1, that promotes histone H3-Lys-56 acetylation by the regulation of Ty1 transposition protein 109 (Rtt109) histone acetyltransferase. Here, we report the x-ray crystal structure of Vps75 and carry out biochemical studies to characterize its interaction with Rtt109. We find that the Vps75 structure forms a homodimeric "headphone" architecture that includes an extended helical dimerization domain and earmuff domains at opposite ends and sides of the dimerization domain. Despite the similar overall architecture with the yeast nucleosome assembly protein 1 and human SET/TAF-1beta/INHAT histone chaperones, Vps75 shows several unique features including the relative disposition of the earmuff domains to the dimerization domain, characteristics of the earmuff domains, and a pronounced cleft at the center of the Vps75 dimer. These differences appear to correlate with the unique function of Vps75 to interact with Rtt109 for histone acetylation. Our biochemical studies reveal that two surfaces on the earmuff domain of Vps75 participate in Rtt109 interaction with a stoichiometry of 2:1, thus leaving the pronounced central cleft of the Vps75 dimer largely accessible for histone binding. Taken together, our data provide a structural framework for understanding how Vps75 mediates both nucleosome assembly and histone acetylation by Rtt109. Structure of Vps75 and implications for histone chaperone function.,Tang Y, Meeth K, Jiang E, Luo C, Marmorstein R Proc Natl Acad Sci U S A. 2008 Aug 26;105(34):12206-11. Epub 2008 Aug 22. PMID:18723682[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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