View source for 1umy


==BHMT from rat liver==
<StructureSection load='1umy' size='340' side='right'caption='[[1umy]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1umy]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1UMY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1UMY 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]] 2.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=1umy FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1umy OCA], [https://pdbe.org/1umy PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1umy RCSB], [https://www.ebi.ac.uk/pdbsum/1umy PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1umy ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/BHMT1_RAT BHMT1_RAT] Involved in the regulation of homocysteine metabolism. Converts betaine and homocysteine to dimethylglycine and methionine, respectively. This reaction is also required for the irreversible oxidation of choline.
== 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/um/1umy_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1umy ConSurf].
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== Publication Abstract from PubMed ==
Betaine homocysteine S-methyltransferase (BHMT) is one of the two enzymes known to methylate homocysteine to generate methionine in the liver. It presents a Zn(2+) atom linked to three essential Cys residues. The crystal structure of rat liver BHMT has been solved at 2.5A resolution, using crystals with P2(1) symmetry and 45% solvent content in the cell. The asymmetric unit contains the whole functional tetramer showing point symmetry 222. The overall fold of the subunit consists mostly of a (alpha/beta)(8) barrel, as for human BHMT. From the end of the barrel, the polypeptide chain extends away and makes many interactions with a different subunit, forming tight dimers. The most remarkable structural feature of rat liver BHMT is the presence of a helix including residues 381-407, at the C terminus of the chain, which bind together the dimers AB to CD. A strong ion-pair and more than 60 hydrophobic interactions keep this helix stacked to the segment 316-349 from the opposite subunit. Moreover, the crystal structure of free rat liver BHMT clearly shows that Tyr160 is the fourth ligand coordinated to Zn, which is replaced by Hcy upon binding. Two residues essential for substrate recognition, Phe76 and Tyr77, are provided by a conformational change in a partially disordered loop (L2). The crucial role of these residues is highlighted by site-directed mutagenesis.

Crystal structure of rat liver betaine homocysteine s-methyltransferase reveals new oligomerization features and conformational changes upon substrate binding.,Gonzalez B, Pajares MA, Martinez-Ripoll M, Blundell TL, Sanz-Aparicio J J Mol Biol. 2004 May 7;338(4):771-82. PMID:15099744<ref>PMID:15099744</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 1umy" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Rattus norvegicus]]
[[Category: Gonzalez B]]
[[Category: Pajares MA]]
[[Category: Sanz-Aparicio J]]