View source for 1g38


==ADENINE-SPECIFIC METHYLTRANSFERASE M. TAQ I/DNA COMPLEX==
<StructureSection load='1g38' size='340' side='right'caption='[[1g38]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1g38]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermus_aquaticus Thermus aquaticus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1G38 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1G38 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=6MA:N6-METHYL-DEOXY-ADENOSINE-5-MONOPHOSPHATE'>6MA</scene>, <scene name='pdbligand=NEA:5-DEOXY-5-[2-(AMINO)ETHYLTHIO]ADENOSINE'>NEA</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=1g38 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1g38 OCA], [https://pdbe.org/1g38 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1g38 RCSB], [https://www.ebi.ac.uk/pdbsum/1g38 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1g38 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MTTA_THEAQ MTTA_THEAQ] This methylase recognizes the double-stranded sequence TCGA, causes specific methylation on A-4 on both strands and protects the DNA from cleavage by the TaqI endonuclease.
== 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/g3/1g38_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=1g38 ConSurf].
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== Publication Abstract from PubMed ==
The 2.0 A crystal structure of the N6-adenine DNA methyltransferase M.TaqI in complex with specific DNA and a nonreactive cofactor analog reveals a previously unrecognized stabilization of the extrahelical target base. To catalyze the transfer of the methyl group from the cofactor S-adenosyl-l-methionine to the 6-amino group of adenine within the double-stranded DNA sequence 5'-TCGA-3', the target nucleoside is rotated out of the DNA helix. Stabilization of the extrahelical conformation is achieved by DNA compression perpendicular to the DNA helix axis at the target base pair position and relocation of the partner base thymine in an interstrand pi-stacked position, where it would sterically overlap with an innerhelical target adenine. The extrahelical target adenine is specifically recognized in the active site, and the 6-amino group of adenine donates two hydrogen bonds to Asn 105 and Pro 106, which both belong to the conserved catalytic motif IV of N6-adenine DNA methyltransferases. These hydrogen bonds appear to increase the partial negative charge of the N6 atom of adenine and activate it for direct nucleophilic attack on the methyl group of the cofactor.

Structure of the N6-adenine DNA methyltransferase M.TaqI in complex with DNA and a cofactor analog.,Goedecke K, Pignot M, Goody RS, Scheidig AJ, Weinhold E Nat Struct Biol. 2001 Feb;8(2):121-5. PMID:11175899<ref>PMID:11175899</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1g38" style="background-color:#fffaf0;"></div>

==See Also==
*[[DNA methyltransferase 3D structures|DNA methyltransferase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Thermus aquaticus]]
[[Category: Goedecke K]]
[[Category: Goody RS]]
[[Category: Pignot M]]
[[Category: Scheidig AJ]]
[[Category: Weinhold E]]