1oqm
From Proteopedia
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| - | [[ | + | ==A 1:1 complex between alpha-lactalbumin and beta1,4-galactosyltransferase in the presence of UDP-N-acetyl-galactosamine== |
| + | <StructureSection load='1oqm' size='340' side='right' caption='[[1oqm]], [[Resolution|resolution]] 2.10Å' scene=''> | ||
| + | == Structural highlights == | ||
| + | <table><tr><td colspan='2'>[[1oqm]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] and [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=1l7w 1l7w]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1OQM OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1OQM FirstGlance]. <br> | ||
| + | </td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=PG4:TETRAETHYLENE+GLYCOL'>PG4</scene>, <scene name='pdbligand=UD2:URIDINE-DIPHOSPHATE-N-ACETYLGALACTOSAMINE'>UD2</scene><br> | ||
| + | <tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">LALBA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=10090 Mus musculus])</td></tr> | ||
| + | <tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Beta-N-acetylglucosaminylglycopeptide_beta-1,4-galactosyltransferase Beta-N-acetylglucosaminylglycopeptide beta-1,4-galactosyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.38 2.4.1.38] </span></td></tr> | ||
| + | <tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1oqm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1oqm OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1oqm RCSB], [http://www.ebi.ac.uk/pdbsum/1oqm PDBsum]</span></td></tr> | ||
| + | <table> | ||
| + | == 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/oq/1oqm_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 == | ||
| + | beta1,4-Galactosyltransferase I (Gal-T1) normally transfers Gal from UDP-Gal to GlcNAc in the presence of Mn(2+) ion. In the presence of alpha-lactalbumin (LA), the Gal acceptor specificity is altered from GlcNAc to Glc. Gal-T1 also transfers GalNAc from UDP-GalNAc to GlcNAc, but with only approximately 0.1% of Gal-T activity. To understand this low GalNAc-transferase activity, we have carried out the crystal structure analysis of the Gal-T1.LA complex with UDP-GalNAc at 2.1-A resolution. The crystal structure reveals that the UDP-GalNAc binding to Gal-T1 is similar to the binding of UDP-Gal to Gal-T1, except for an additional hydrogen bond formed between the N-acetyl group of GalNAc moiety with the Tyr-289 side chain hydroxyl group. Elimination of this additional hydrogen bond by mutating Tyr-289 residue to Leu, Ile, or Asn enhances the GalNAc-transferase activity. Although all three mutants exhibit enhanced GalNAc-transferase activity, the mutant Y289L exhibits GalNAc-transferase activity that is nearly 100% of its Gal-T activity, even while completely retaining its Gal-T activity. The steady state kinetic analyses on the Leu-289 mutant indicate that the K(m) for GlcNAc has increased compared to the wild type. On the other hand, the catalytic constant (k(cat)) in the Gal-T reaction is comparable with the wild type, whereas it is 3-5-fold higher in the GalNAc-T reaction. Interestingly, in the presence of LA, these mutants also transfer GalNAc to Glc instead of to GlcNAc. The present study demonstrates that, in the Gal-T family, the Tyr-289/Phe-289 residue largely determines the sugar donor specificity. | ||
| - | + | Structure-based design of beta 1,4-galactosyltransferase I (beta 4Gal-T1) with equally efficient N-acetylgalactosaminyltransferase activity: point mutation broadens beta 4Gal-T1 donor specificity.,Ramakrishnan B, Qasba PK J Biol Chem. 2002 Jun 7;277(23):20833-9. Epub 2002 Mar 26. PMID:11916963<ref>PMID:11916963</ref> | |
| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | + | </div> | |
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==See Also== | ==See Also== | ||
| - | *[[ | + | *[[Glycosyltransferase|Glycosyltransferase]] |
*[[Lactalbumin|Lactalbumin]] | *[[Lactalbumin|Lactalbumin]] | ||
| - | + | == References == | |
| - | == | + | <references/> |
| - | < | + | __TOC__ |
| + | </StructureSection> | ||
[[Category: Beta-N-acetylglucosaminylglycopeptide beta-1,4-galactosyltransferase]] | [[Category: Beta-N-acetylglucosaminylglycopeptide beta-1,4-galactosyltransferase]] | ||
[[Category: Bos taurus]] | [[Category: Bos taurus]] | ||
Revision as of 22:35, 28 September 2014
A 1:1 complex between alpha-lactalbumin and beta1,4-galactosyltransferase in the presence of UDP-N-acetyl-galactosamine
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