2hhs: Difference between revisions
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[[Image: | ==O6-methyl:C pair in the polymerase-10 basepair position== | ||
<StructureSection load='2hhs' size='340' side='right' caption='[[2hhs]], [[Resolution|resolution]] 1.80Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2hhs]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/Geobacillus_stearothermophilus Geobacillus stearothermophilus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HHS OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2HHS FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=SUC:SUCROSE'>SUC</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=6OG:6-O-METHYL+GUANOSINE-5-MONOPHOSPHATE'>6OG</scene></td></tr> | |||
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2hhq|2hhq]], [[2hht|2hht]], [[2hhu|2hhu]], [[2hhv|2hhv]], [[2hhw|2hhw]], [[2hhx|2hhx]], [[2hhy|2hhy]]</td></tr> | |||
<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">polA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1422 Geobacillus stearothermophilus])</td></tr> | |||
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/DNA-directed_DNA_polymerase DNA-directed DNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.7 2.7.7.7] </span></td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2hhs FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hhs OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2hhs RCSB], [http://www.ebi.ac.uk/pdbsum/2hhs PDBsum]</span></td></tr> | |||
<table> | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/hh/2hhs_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Methylating agents are widespread environmental carcinogens that generate a broad spectrum of DNA damage. Methylation at the guanine O(6) position confers the greatest mutagenic and carcinogenic potential. DNA polymerases insert cytosine and thymine with similar efficiency opposite O(6)-methyl-guanine (O6MeG). We combined pre-steady-state kinetic analysis and a series of nine x-ray crystal structures to contrast the reaction pathways of accurate and mutagenic replication of O6MeG in a high-fidelity DNA polymerase from Bacillus stearothermophilus. Polymerases achieve substrate specificity by selecting for nucleotides with shape and hydrogen-bonding patterns that complement a canonical DNA template. Our structures reveal that both thymine and cytosine O6MeG base pairs evade proofreading by mimicking the essential molecular features of canonical substrates. The steric mimicry depends on stabilization of a rare cytosine tautomer in C.O6MeG-polymerase complexes. An unusual electrostatic interaction between O-methyl protons and a thymine carbonyl oxygen helps stabilize T.O6MeG pairs bound to DNA polymerase. Because DNA methylators constitute an important class of chemotherapeutic agents, the molecular mechanisms of replication of these DNA lesions are important for our understanding of both the genesis and treatment of cancer. | |||
The structural basis for the mutagenicity of O(6)-methyl-guanine lesions.,Warren JJ, Forsberg LJ, Beese LS Proc Natl Acad Sci U S A. 2006 Dec 26;103(52):19701-6. Epub 2006 Dec 18. PMID:17179038<ref>PMID:17179038</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[DNA polymerase|DNA polymerase]] | *[[DNA polymerase|DNA polymerase]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: DNA-directed DNA polymerase]] | [[Category: DNA-directed DNA polymerase]] | ||
[[Category: Geobacillus stearothermophilus]] | [[Category: Geobacillus stearothermophilus]] | ||
Revision as of 07:45, 29 September 2014
O6-methyl:C pair in the polymerase-10 basepair positionO6-methyl:C pair in the polymerase-10 basepair position
Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedMethylating agents are widespread environmental carcinogens that generate a broad spectrum of DNA damage. Methylation at the guanine O(6) position confers the greatest mutagenic and carcinogenic potential. DNA polymerases insert cytosine and thymine with similar efficiency opposite O(6)-methyl-guanine (O6MeG). We combined pre-steady-state kinetic analysis and a series of nine x-ray crystal structures to contrast the reaction pathways of accurate and mutagenic replication of O6MeG in a high-fidelity DNA polymerase from Bacillus stearothermophilus. Polymerases achieve substrate specificity by selecting for nucleotides with shape and hydrogen-bonding patterns that complement a canonical DNA template. Our structures reveal that both thymine and cytosine O6MeG base pairs evade proofreading by mimicking the essential molecular features of canonical substrates. The steric mimicry depends on stabilization of a rare cytosine tautomer in C.O6MeG-polymerase complexes. An unusual electrostatic interaction between O-methyl protons and a thymine carbonyl oxygen helps stabilize T.O6MeG pairs bound to DNA polymerase. Because DNA methylators constitute an important class of chemotherapeutic agents, the molecular mechanisms of replication of these DNA lesions are important for our understanding of both the genesis and treatment of cancer. The structural basis for the mutagenicity of O(6)-methyl-guanine lesions.,Warren JJ, Forsberg LJ, Beese LS Proc Natl Acad Sci U S A. 2006 Dec 26;103(52):19701-6. Epub 2006 Dec 18. PMID:17179038[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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