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8etu
From Proteopedia
Class2 of the INO80-Hexasome complex
Structural highlights
FunctionRUVB2_YEAST DNA helicase which participates in several chromatin remodeling complexes, including the SWR1 and the INO80 complexes. The SWR1 complex mediates the ATP-dependent exchange of histone H2A for the H2A variant HZT1 leading to transcriptional regulation of selected genes by chromatin remodeling. The INO80 complex remodels chromatin by shifting nucleosomes. Its ability to induce transcription of some phosphate-responsive genes is modulated by inositol polyphosphates. The INO80 complex is involved in DNA repair by associating to 'Ser-129' phosphorylated H2A histones as a response to DNA damage. During transcription may recruit SPT15/TBP to the TATA-boxes of involved genes. Required for box C/D and box H/ACA snoRNA accumulation and involved in pre-rRNA processing.[1] [2] [3] [4] [5] [6] [7] [8] [9] Publication Abstract from PubMedUnlike other chromatin remodelers, INO80 preferentially mobilizes hexasomes, which can form during transcription. Why INO80 prefers hexasomes over nucleosomes remains unclear. Here, we report structures of S. cerevisiae INO80 bound to a hexasome or a nucleosome. INO80 binds the two substrates in substantially different orientations. On a hexasome, INO80 places its ATPase subunit, Ino80, at superhelical location (SHL)-2, across from SHL-6/-7 as previously seen on nucleosomes. Our results suggest that INO80 action on hexasomes resembles action by other remodelers on nucleosomes, such that Ino80 is maximally active near SHL-2. The SHL-2 position also plays a critical role for nucleosome remodeling by INO80. Overall, the mechanistic adaptations used by INO80 for preferential hexasome sliding imply that sub-nucleosomal particles play considerable regulatory roles. Reorientation of INO80 on hexasomes reveals basis for mechanistic versatility.,Wu H, Munoz EN, Hsieh LJ, Chio US, Gourdet MA, Narlikar GJ, Cheng Y Science. 2023 Jun 28. doi: 10.1126/science.adf4197. PMID:37384669[10] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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