4ymo: Difference between revisions
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==Structure of human DNA polymerase beta complexed with N7BG in the template opposite to incoming non-hydrolyzable CTP WITH MANGANESE IN THE ACTIVE SITE== | ==Structure of human DNA polymerase beta complexed with N7BG in the template opposite to incoming non-hydrolyzable CTP WITH MANGANESE IN THE ACTIVE SITE== | ||
<StructureSection load='4ymo' size='340' side='right' caption='[[4ymo]], [[Resolution|resolution]] 2.15Å' scene=''> | <StructureSection load='4ymo' size='340' side='right'caption='[[4ymo]], [[Resolution|resolution]] 2.15Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[4ymo]] is a 4 chain structure with sequence from [ | <table><tr><td colspan='2'>[[4ymo]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4YMO OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4YMO FirstGlance]. <br> | ||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=0KX:2-DEOXY-5-O-[(R)-HYDROXY{[(R)-HYDROXY(PHOSPHONOOXY)PHOSPHORYL]AMINO}PHOSPHORYL]CYTIDINE'>0KX</scene>, | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=0KX:2-DEOXY-5-O-[(R)-HYDROXY{[(R)-HYDROXY(PHOSPHONOOXY)PHOSPHORYL]AMINO}PHOSPHORYL]CYTIDINE'>0KX</scene>, <scene name='pdbligand=7BG:2-AMINO-7-BENZYL-9-(2-DEOXY-2-FLUORO-5-O-PHOSPHONO-BETA-D-ARABINOFURANOSYL)-6-OXO-6,9-DIHYDRO-1H-PURIN-7-IUM'>7BG</scene>, <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</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=4ymo FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ymo OCA], [https://pdbe.org/4ymo PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4ymo RCSB], [https://www.ebi.ac.uk/pdbsum/4ymo PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4ymo 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/DPOLB_HUMAN DPOLB_HUMAN] Repair polymerase that plays a key role in base-excision repair. Has 5'-deoxyribose-5-phosphate lyase (dRP lyase) activity that removes the 5' sugar phosphate and also acts as a DNA polymerase that adds one nucleotide to the 3' end of the arising single-nucleotide gap. Conducts 'gap-filling' DNA synthesis in a stepwise distributive fashion rather than in a processive fashion as for other DNA polymerases.<ref>PMID:9207062</ref> <ref>PMID:9572863</ref> <ref>PMID:11805079</ref> <ref>PMID:21362556</ref> | ||
<div style="background-color:#fffaf0;"> | <div style="background-color:#fffaf0;"> | ||
== Publication Abstract from PubMed == | == Publication Abstract from PubMed == | ||
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==See Also== | ==See Also== | ||
*[[DNA polymerase|DNA polymerase]] | *[[DNA polymerase 3D structures|DNA polymerase 3D structures]] | ||
== References == | == References == | ||
<references/> | <references/> | ||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
[[Category: | [[Category: Homo sapiens]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: | [[Category: Koag M-C]] | ||
[[Category: | [[Category: Lee S]] | ||
Revision as of 11:19, 3 May 2023
Structure of human DNA polymerase beta complexed with N7BG in the template opposite to incoming non-hydrolyzable CTP WITH MANGANESE IN THE ACTIVE SITEStructure of human DNA polymerase beta complexed with N7BG in the template opposite to incoming non-hydrolyzable CTP WITH MANGANESE IN THE ACTIVE SITE
Structural highlights
FunctionDPOLB_HUMAN Repair polymerase that plays a key role in base-excision repair. Has 5'-deoxyribose-5-phosphate lyase (dRP lyase) activity that removes the 5' sugar phosphate and also acts as a DNA polymerase that adds one nucleotide to the 3' end of the arising single-nucleotide gap. Conducts 'gap-filling' DNA synthesis in a stepwise distributive fashion rather than in a processive fashion as for other DNA polymerases.[1] [2] [3] [4] Publication Abstract from PubMedA wide variety of endogenous and exogenous alkylating agents attack DNA to preferentially generate N7-alkylguanine (N7-alkylG) adducts. Studies on the effect of N7-alkylG lesions on biological processes have been difficult due in part to complications arising from the chemical lability of the positively charged N7-alkylG, which can readily produce secondary lesions. To assess the effect of bulky N7-alkylG on DNA replication, we prepared chemically stable N7-benzylguanine(N7bnG)-containing DNA and evaluated nucleotide incorporation opposite the lesion by human DNA polymerase beta (polbeta), a model enzyme for high-fidelity DNA polymerases. Kinetic studies showed that the N7-benzyl-G lesion greatly inhibited dCTP incorporation by polbeta. The crystal structure of polbeta incorporating dCTP opposite N7bnG showed a Watson-Crick N7bnG:dCTP. The polbeta-N7bnG:dCTP structure showed an open protein conformation, a relatively disordered dCTP, and lack of catalytic metal, which explained the inefficient nucleotide incorporation opposite N7bnG. This indicates that polbeta is sensitive to major groove adducts in the templating-base side and deters nucleotide incorporation opposite bulky N7-alkylG adducts by adopting a catalytically incompetent conformation. Substituting Mg2+ for Mn2+ induced an open-to-closed conformational change due to the presence of catalytic metal and stably bound dCTP and increased the catalytic efficiency by ~10-fold, highlighting the effect of binding of incoming nucleotide and catalytic metal on protein not conformation and nucleotidyl transfer reaction. Overall, these results suggest that, although bulky alkyl groups at guanine-N7 may not alter base-pairing properties of guanine, the major-groove-positioned lesions in the template could impede nucleotidyl transfer by some DNA polymerases. Structural and kinetic studies of the effect of guanine-N7 alkylation and metal cofactors on DNA replication.,Kou Y, Koag MC, Lee S Biochemistry. 2018 Jun 29. doi: 10.1021/acs.biochem.8b00331. PMID:29957995[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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