3d4v: Difference between revisions
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[[Image: | ==Crystal Structure of an AlkA Host/Guest Complex N7MethylGuanine:Cytosine Base Pair== | ||
<StructureSection load='3d4v' size='340' side='right' caption='[[3d4v]], [[Resolution|resolution]] 2.90Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3d4v]] is a 8 chain structure with sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3D4V OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3D4V FirstGlance]. <br> | |||
</td></tr><tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=FMG:2-AMINO-9-(2-DEOXY-2-FLUORO-5-O-PHOSPHONO-BETA-D-ARABINOFURANOSYL)-7-METHYL-6-OXO-6,9-DIHYDRO-1H-PURIN-7-IUM'>FMG</scene></td></tr> | |||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">alkA, aidA, b2068, JW2053 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli])</td></tr> | |||
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/DNA-3-methyladenine_glycosylase_II DNA-3-methyladenine glycosylase II], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.2.21 3.2.2.21] </span></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3d4v FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3d4v OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3d4v RCSB], [http://www.ebi.ac.uk/pdbsum/3d4v PDBsum]</span></td></tr> | |||
</table> | |||
== Function == | |||
[[http://www.uniprot.org/uniprot/3MG2_ECOLI 3MG2_ECOLI]] Hydrolysis of the deoxyribose N-glycosidic bond to excise 3-methyladenine, 3-methylguanine, 7-methylguanine, O2-methylthymine, and O2-methylcytosine from the damaged DNA polymer formed by alkylation lesions. | |||
== 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/d4/3d4v_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 == | |||
The predominant product of aberrant DNA methylation is the genotoxic lesion N7-methyl-2'-deoxyguanosine (m7dG). M7dG is recognized and excised by lesion-specific DNA glycosylases, namely AlkA in E. coli and Aag in humans. Structural studies of m7dG recognition and catalysis by these enzymes have been hampered due to a lack of efficient means by which to incorporate the chemically labile m7dG moiety site-specifically into DNA on a preparative scale. Here we report a solution to this problem. We stabilized the lesion toward acid-catalyzed and glycosylase-catalyzed depurination by 2'-fluorination and toward base-catalyzed degradation using mild, nonaqueous conditions in the DNA deprotection reaction. Duplex DNA containing 2'-fluoro-m7dG (Fm7dG) cocrystallized with AlkA as a host-guest complex in which the lesion-containing segment of DNA was nearly devoid of protein contacts, thus enabling the first direct visualization of the N7-methylguanine lesion nucleobase in DNA. The structure reveals that the base-pairing mode of Fm7dG:C is nearly identical to that of G:C, and Fm7dG does not induce any apparent structural disturbance of the duplex structure. These observations suggest that AlkA and Aag must perform a structurally invasive interrogation of DNA in order to detect the presence of intrahelical m7dG lesions. | |||
Synthesis and structure of duplex DNA containing the genotoxic nucleobase lesion N7-methylguanine.,Lee S, Bowman BR, Ueno Y, Wang S, Verdine GL J Am Chem Soc. 2008 Sep 3;130(35):11570-1. Epub 2008 Aug 8. PMID:18686953<ref>PMID:18686953</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[DNA | *[[DNA glycosylase|DNA glycosylase]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: DNA-3-methyladenine glycosylase II]] | [[Category: DNA-3-methyladenine glycosylase II]] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Bowman, B R | [[Category: Bowman, B R]] | ||
[[Category: Lee, S | [[Category: Lee, S]] | ||
[[Category: Verdine, G L | [[Category: Verdine, G L]] | ||
[[Category: Wang, S | [[Category: Wang, S]] | ||
[[Category: Alka]] | [[Category: Alka]] | ||
[[Category: Dna damage]] | [[Category: Dna damage]] | ||
