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[[Image:2hhq.gif|left|200px]]


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==O6-methyl-guanine:T pair in the polymerase-10 basepair position==
The line below this paragraph, containing "STRUCTURE_2hhq", creates the "Structure Box" on the page.
<StructureSection load='2hhq' size='340' side='right'caption='[[2hhq]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
You may change the PDB parameter (which sets the PDB file loaded into the applet)
== Structural highlights ==
or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
<table><tr><td colspan='2'>[[2hhq]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Geobacillus_stearothermophilus Geobacillus stearothermophilus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HHQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2HHQ FirstGlance]. <br>
or leave the SCENE parameter empty for the default display.
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.8&#8491;</td></tr>
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<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=6OG:6-O-METHYL+GUANOSINE-5-MONOPHOSPHATE'>6OG</scene>, <scene name='pdbligand=FRU:FRUCTOSE'>FRU</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PRD_900003:sucrose'>PRD_900003</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
{{STRUCTURE_2hhq| PDB=2hhq |  SCENE= }}
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2hhq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hhq OCA], [https://pdbe.org/2hhq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2hhq RCSB], [https://www.ebi.ac.uk/pdbsum/2hhq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2hhq ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q45458_GEOSE Q45458_GEOSE] In addition to polymerase activity, this DNA polymerase exhibits 5'-3' exonuclease activity.[RuleBase:RU004460]
== 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/2hhq_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/main_output.php?pdb_ID=2hhq ConSurf].
<div style="clear:both"></div>


'''O6-methyl-guanine:T pair in the polymerase-10 basepair position'''
==See Also==
 
*[[DNA polymerase 3D structures|DNA polymerase 3D structures]]
 
__TOC__
==Overview==
</StructureSection>
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.
 
==About this Structure==
2HHQ is a [[Single protein]] structure of 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=2HHQ OCA].
 
==Reference==
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:[http://www.ncbi.nlm.nih.gov/pubmed/17179038 17179038]
[[Category: DNA-directed DNA polymerase]]
[[Category: Geobacillus stearothermophilus]]
[[Category: Geobacillus stearothermophilus]]
[[Category: Single protein]]
[[Category: Large Structures]]
[[Category: Beese, L S.]]
[[Category: Beese LS]]
[[Category: Forsberg, L J.]]
[[Category: Forsberg LJ]]
[[Category: Warren, J J.]]
[[Category: Warren JJ]]
[[Category: Dna polymerase i]]
[[Category: Dna replication]]
[[Category: Klenow fragment]]
[[Category: O6-methyl-guanine]]
[[Category: Protein-dna complex]]
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May  4 06:18:31 2008''

Latest revision as of 12:32, 14 February 2024

O6-methyl-guanine:T pair in the polymerase-10 basepair positionO6-methyl-guanine:T pair in the polymerase-10 basepair position

Structural highlights

2hhq is a 3 chain structure with sequence from Geobacillus stearothermophilus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.8Å
Ligands:, , , , ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

Q45458_GEOSE In addition to polymerase activity, this DNA polymerase exhibits 5'-3' exonuclease activity.[RuleBase:RU004460]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

See Also

2hhq, resolution 1.80Å

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