The Gcn5 histone acetyltransferase (HAT) subunit of the SAGA transcriptional coactivator complex catalyzes acetylation of histone H3 and H2B N-terminal tails, posttranslational modifications associated with gene activation. Binding of the SAGA subunit partner Ada2 to Gcn5 activates Gcn5's intrinsically weak HAT activity on histone proteins, but the mechanism for this activation by the Ada2 SANT domain has remained elusive. We have employed Fab antibody fragments as crystallization chaperones to determine crystal structures of a yeast Ada2/Gcn5 complex. Our structural and biochemical results indicate that the Ada2 SANT domain does not activate Gcn5's activity by directly affecting histone peptide binding as previously proposed. Instead, the Ada2 SANT domain enhances Gcn5 binding of the enzymatic cosubstrate acetyl-CoA. This finding suggests a mechanism for regulating chromatin modification enzyme activity: controlling binding of the modification cosubstrate instead of the histone substrate.
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http://dx.doi.org/10.1073/pnas.1805343115 | DOI Listing |
Commun Biol
October 2023
State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, 100 Daxue Road, Nanning, Guangxi, 530004, PR China.
Filamentous fungus can produce raw-starch-degrading enzyme (RSDE) that efficiently degrades raw starch below starch gelatinization temperature. Employment of RSDE in starch processing can save energy. A key putative transcription factor PoxRsrA (production of raw-starch-degrading enzyme regulation in Penicillium oxalicum) was identified to regulate RSDE production in P.
View Article and Find Full Text PDFMed Clin (Barc)
September 2022
Sección de Reumatología Pediátrica, Servicio de Pediatría, Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona, España.
Cell Cycle
September 2021
Department of Botany, UGC Centre for Advanced Studies, the University of Burdwan, Golapbag Campus, Burdwan, West Bengal, India.
Plants, with their obligatory immobility, are vastly exposed to a wide range of environmental agents and also various endogenous processes, which frequently cause damage to DNA and impose genotoxic stress. These factors subsequently increase genome instability, thus affecting plant growth and productivity. Therefore, to survive under frequent and extreme environmental stress conditions, plants have developed highly efficient and powerful defense mechanisms to repair the damages in the genome for maintaining genome stability.
View Article and Find Full Text PDFJ Biol Chem
September 2019
Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208-3500
The constitutively nuclear histone deacetylases (HDACs) 1, 2, and 3 erase acetyl marks on acetyllysine residues, alter the landscape of histone modifications, and modulate chromatin structure and dynamics and thereby crucially regulate gene transcription in higher eukaryotes. Nuclear HDACs exist as at least six giant multiprotein complexes whose nonenzymatic subunits confer genome targeting specificity for these enzymes. The deacetylase activity of HDACs has been shown previously to be enhanced by inositol phosphates, which also bridge the catalytic domain in protein-protein interactions with SANT (Swi3, Ada2, N-Cor, and TFIIIB) domains in all HDAC complexes except those that contain the Sin3 transcriptional corepressors.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
October 2018
Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802;
The Gcn5 histone acetyltransferase (HAT) subunit of the SAGA transcriptional coactivator complex catalyzes acetylation of histone H3 and H2B N-terminal tails, posttranslational modifications associated with gene activation. Binding of the SAGA subunit partner Ada2 to Gcn5 activates Gcn5's intrinsically weak HAT activity on histone proteins, but the mechanism for this activation by the Ada2 SANT domain has remained elusive. We have employed Fab antibody fragments as crystallization chaperones to determine crystal structures of a yeast Ada2/Gcn5 complex.
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