5i9e
From Proteopedia
Crystal structure of a nuclear actin ternary complex
Structural highlights
FunctionARP4_YEAST Chromatin interaction component of the NuA4 histone acetyltransferase complex which is involved in transcriptional activation of selected genes principally by acetylation of nucleosomal histone H4 and H2A. The NuA4 complex is also involved in DNA repair. ARP4 recognizes H2AS128ph (gamma-H2A) and is required for NuA4 complex integrity. Component of the SWR1 complex which mediates the ATP-dependent exchange of histone H2A for the H2A variant HZT1 leading to transcriptional regulation of selected genes by chromatin remodeling. Component of the INO80 complex which 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 gamma-H2A as a response to DNA damage.[1] [2] [3] [4] [5] [6] [7] [8] [9] Publication Abstract from PubMedActin polymerizes and forms filamentous structures (F-actin) in the cytoplasm of eukaryotic cells. It also exists in the nucleus and regulates various nucleic acid transactions, particularly through its incorporation into multiple chromatin-remodeling complexes. However, the specific structure of actin and the mechanisms that regulate its polymeric nature inside the nucleus remain unknown. Here, we report the crystal structure of nuclear actin (N-actin) complexed with actin-related protein 4 (Arp4) and the helicase-SANT-associated (HSA) domain of the chromatin remodeler Swr1. The inner face and barbed end of N-actin are sequestered by interactions with Arp4 and the HSA domain, respectively, which prevents N-actin from polymerization and binding to many actin regulators. The two major domains of N-actin are more twisted than those of globular actin (G-actin), and its nucleotide-binding pocket is occluded, freeing N-actin from binding to and regulation by ATP. These findings revealed the salient structural features of N-actin that distinguish it from its cytoplasmic counterpart and provide a rational basis for its functions and regulation inside the nucleus. Crystal structure of a nuclear actin ternary complex.,Cao T, Sun L, Jiang Y, Huang S, Wang J, Chen Z Proc Natl Acad Sci U S A. 2016 Aug 9;113(32):8985-90. doi:, 10.1073/pnas.1602818113. Epub 2016 Jul 25. PMID:27457955[10] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. Loading citation details.. Citations 11 reviews cite this structure No citations found See AlsoReferences
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