5dc6: Difference between revisions
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<StructureSection load='5dc6' size='340' side='right'caption='[[5dc6]], [[Resolution|resolution]] 1.55Å' scene=''> | <StructureSection load='5dc6' size='340' side='right'caption='[[5dc6]], [[Resolution|resolution]] 1.55Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[5dc6]] is a 4 chain structure with sequence from [ | <table><tr><td colspan='2'>[[5dc6]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5DC6 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5DC6 FirstGlance]. <br> | ||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</scene>, <scene name='pdbligand=ALY:N(6)-ACETYLLYSINE'>ALY</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=MCM:7-AMINO-4-METHYL-CHROMEN-2-ONE'>MCM</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr> | ||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=5dc6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5dc6 OCA], [https://pdbe.org/5dc6 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5dc6 RCSB], [https://www.ebi.ac.uk/pdbsum/5dc6 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5dc6 ProSAT]</span></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[ | |||
</table> | </table> | ||
== Function == | == Function == | ||
[ | [https://www.uniprot.org/uniprot/HDAC8_HUMAN HDAC8_HUMAN] Responsible for the deacetylation of lysine residues on the N-terminal part of the core histones (H2A, H2B, H3 and H4). Histone deacetylation gives a tag for epigenetic repression and plays an important role in transcriptional regulation, cell cycle progression and developmental events. Histone deacetylases act via the formation of large multiprotein complexes. May play a role in smooth muscle cell contractility.<ref>PMID:10748112</ref> <ref>PMID:10926844</ref> <ref>PMID:10922473</ref> <ref>PMID:14701748</ref> | ||
<div style="background-color:#fffaf0;"> | <div style="background-color:#fffaf0;"> | ||
== Publication Abstract from PubMed == | == Publication Abstract from PubMed == | ||
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__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
[[Category: | [[Category: Homo sapiens]] | ||
[[Category: Large Structures]] | [[Category: Large Structures]] | ||
[[Category: | [[Category: Synthetic construct]] | ||
[[Category: | [[Category: Christianson DW]] | ||
[[Category: | [[Category: Decroos C]] | ||
[[Category: | [[Category: Lee MS]] | ||
Revision as of 13:29, 21 June 2023
Crystal structure of D176N-Y306F HDAC8 in complex with a tetrapeptide substrateCrystal structure of D176N-Y306F HDAC8 in complex with a tetrapeptide substrate
Structural highlights
FunctionHDAC8_HUMAN Responsible for the deacetylation of lysine residues on the N-terminal part of the core histones (H2A, H2B, H3 and H4). Histone deacetylation gives a tag for epigenetic repression and plays an important role in transcriptional regulation, cell cycle progression and developmental events. Histone deacetylases act via the formation of large multiprotein complexes. May play a role in smooth muscle cell contractility.[1] [2] [3] [4] Publication Abstract from PubMedHistone deacetylases (HDACs) regulate cellular processes such as differentiation and apoptosis and are targeted by anticancer therapeutics in development and in the clinic. HDAC8 is a metal-dependent class I HDAC and is proposed to use a general acid-base catalytic pair in the mechanism of amide bond hydrolysis. Here, we report site-directed mutagenesis and enzymological measurements to elucidate the catalytic mechanism of HDAC8. Specifically, we focus on the catalytic function of Y306 and the histidine-aspartate dyads H142-D176 and H143-D183. Additionally, we report X-ray crystal structures of four representative HDAC8 mutants: D176N, D176N/Y306F, D176A/Y306F, and H142A/Y306F. These structures provide a useful framework for understanding enzymological measurements. The pH dependence of kcat/KM for wild-type Co(II)-HDAC8 is bell-shaped with two pKa values of 7.4 and 10.0. The upper pKa reflects the ionization of the metal-bound water molecule and shifts to 9.1 in Zn(II)-HDAC8. The H142A mutant has activity 230-fold lower than that of wild-type HDAC8, but the pKa1 value is not altered. Y306F HDAC8 is 150-fold less active than the wild-type enzyme; crystal structures show that Y306 hydrogen bonds with the zinc-bound substrate carbonyl, poised for transition state stabilization. The H143A and H142A/H143A mutants exhibit activity that is >80000-fold lower than that of wild-type HDAC8; the buried D176N and D176A mutants have significant catalytic effects, with more subtle effects caused by D183N and D183A. These enzymological and structural studies strongly suggest that H143 functions as a single general base-general acid catalyst, while H142 remains positively charged and serves as an electrostatic catalyst for transition state stabilization. General Base-General Acid Catalysis in Human Histone Deacetylase 8.,Gantt SM Fsgm, Decroos C, Lee MS, Gullett LE, Bowman CM, Christianson DW, Fierke CA Biochemistry. 2016 Jan 25. PMID:26806311[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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