View source for 1snz


==Crystal structure of apo human galactose mutarotase==
<StructureSection load='1snz' size='340' side='right'caption='[[1snz]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1snz]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SNZ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1SNZ 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]] 2.2&#8491;</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=1snz FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1snz OCA], [https://pdbe.org/1snz PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1snz RCSB], [https://www.ebi.ac.uk/pdbsum/1snz PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1snz ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/GALM_HUMAN GALM_HUMAN] Mutarotase converts alpha-aldose to the beta-anomer. It is active on D-glucose, L-arabinose, D-xylose, D-galactose, maltose and lactose (By similarity).<ref>PMID:12753898</ref> <ref>PMID:15026423</ref> 
== 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/sn/1snz_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=1snz ConSurf].
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== Publication Abstract from PubMed ==
Galactose mutarotase catalyzes the conversion of beta-d-galactose to alpha-d-galactose during normal galactose metabolism. The enzyme has been isolated from bacteria, plants, and animals and is present in the cytoplasm of most cells. Here we report the x-ray crystallographic analysis of human galactose mutarotase both in the apoform and complexed with its substrate, beta-d-galactose. The polypeptide chain folds into an intricate array of 29 beta-strands, 25 classical reverse turns, and 2 small alpha-helices. There are two cis-peptide bonds at Arg-78 and Pro-103. The sugar ligand sits in a shallow cleft and is surrounded by Asn-81, Arg-82, His-107, His-176, Asp-243, Gln-279, and Glu-307. Both the side chains of Glu-307 and His-176 are in the proper location to act as a catalytic base and a catalytic acid, respectively. These residues are absolutely conserved among galactose mutarotases. To date, x-ray models for three mutarotases have now been reported, namely that described here and those from Lactococcus lactis and Caenorhabditis elegans. The molecular architectures of these enzymes differ primarily in the loop regions connecting the first two beta-strands. In the human protein, there are six extra residues in the loop compared with the bacterial protein for an approximate longer length of 9 A. In the C. elegans protein, the first 17 residues are missing, thereby reducing the total number of beta-strands by one.

Molecular structure of human galactose mutarotase.,Thoden JB, Timson DJ, Reece RJ, Holden HM J Biol Chem. 2004 May 28;279(22):23431-7. Epub 2004 Mar 16. PMID:15026423<ref>PMID:15026423</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Galactose mutarotase|Galactose mutarotase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Holden HM]]
[[Category: Reece RJ]]
[[Category: Thoden JB]]
[[Category: Timson DJ]]