View source for 9mht


==CYTOSINE-SPECIFIC METHYLTRANSFERASE HHAI/DNA COMPLEX==
<StructureSection load='9mht' size='340' side='right'caption='[[9mht]], [[Resolution|resolution]] 2.39&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9mht]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Haemophilus_haemolyticus Haemophilus haemolyticus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9MHT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9MHT 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]] 2.39&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=3DR:1,2-DIDEOXYRIBOFURANOSE-5-PHOSPHATE'>3DR</scene>, <scene name='pdbligand=SAH:S-ADENOSYL-L-HOMOCYSTEINE'>SAH</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=9mht FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9mht OCA], [https://pdbe.org/9mht PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9mht RCSB], [https://www.ebi.ac.uk/pdbsum/9mht PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9mht ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MTH1_HAEPH MTH1_HAEPH] This methylase recognizes the double-stranded sequence GCGC, causes specific methylation on C-2 on both strands, and protects the DNA from cleavage by the HhaI 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/mh/9mht_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=9mht ConSurf].
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== Publication Abstract from PubMed ==
Three structures have been determined for complexes between HhaI methyltransferase (M.HhaI) and oligonucleotides containing a G:A, G:U or G:AP (AP = abasic or apurinic/apyrimidinic) mismatch at the target base pair. The mismatched adenine, uracil and abasic site are all flipped out of the DNA helix and located in the enzyme's active-site pocket, adopting the same conformation as in the flipped-out normal substrate. These results, particularly the flipped-out abasic deoxyribose sugar, provide insight into the mechanism of base flipping. If the process involves the protein pushing the base out of the helix, then the push must take place not on the base, but rather on the sugar-phosphate backbone. Thus rotation of the DNA backbone is probably the key to base flipping.

Structures of HhaI methyltransferase complexed with substrates containing mismatches at the target base.,O'Gara M, Horton JR, Roberts RJ, Cheng X Nat Struct Biol. 1998 Oct;5(10):872-7. PMID:9783745<ref>PMID:9783745</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 9mht" style="background-color:#fffaf0;"></div>

==See Also==
*[[DNA methyltransferase 3D structures|DNA methyltransferase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Haemophilus haemolyticus]]
[[Category: Large Structures]]
[[Category: Cheng X]]
[[Category: Horton JR]]
[[Category: O'Gara M]]
[[Category: Roberts RJ]]