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| - | [[Image:1z9a.gif|left|200px]] | |
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| - | {{Structure
| + | ==Crystal Structure Of The Asn-309 To Asp Mutant Of Candida Tenuis Xylose Reductase (Akr2B5) Bound To Nad+== |
| - | |PDB= 1z9a |SIZE=350|CAPTION= <scene name='initialview01'>1z9a</scene>, resolution 2.40Å
| + | <StructureSection load='1z9a' size='340' side='right'caption='[[1z9a]], [[Resolution|resolution]] 2.40Å' scene=''> |
| - | |SITE=
| + | == Structural highlights == |
| - | |LIGAND= <scene name='pdbligand=NAD:NICOTINAMIDE-ADENINE-DINUCLEOTIDE'>NAD</scene> | + | <table><tr><td colspan='2'>[[1z9a]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Yamadazyma_tenuis Yamadazyma tenuis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1Z9A OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1Z9A FirstGlance]. <br> |
| - | |ACTIVITY=
| + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.4Å</td></tr> |
| - | |GENE= XYL1, XYLR ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=45596 Candida tenuis])
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NAD:NICOTINAMIDE-ADENINE-DINUCLEOTIDE'>NAD</scene></td></tr> |
| - | |DOMAIN=
| + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1z9a FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1z9a OCA], [https://pdbe.org/1z9a PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1z9a RCSB], [https://www.ebi.ac.uk/pdbsum/1z9a PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1z9a ProSAT]</span></td></tr> |
| - | |RELATEDENTRY=
| + | </table> |
| - | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1z9a FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1z9a OCA], [http://www.ebi.ac.uk/pdbsum/1z9a PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1z9a RCSB]</span>
| + | == Function == |
| - | }}
| + | [https://www.uniprot.org/uniprot/XYL1_CANTE XYL1_CANTE] Reduces D-xylose into xylitol. Has a preference for NADPH, but can also utilize NADH as cosubstrate. |
| - | | + | == Evolutionary Conservation == |
| - | '''Crystal Structure Of The Asn-309 To Asp Mutant Of Candida Tenuis Xylose Reductase (Akr2B5) Bound To Nad+'''
| + | [[Image:Consurf_key_small.gif|200px|right]] |
| - | | + | Check<jmol> |
| - | | + | <jmolCheckbox> |
| - | ==Overview== | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/z9/1z9a_consurf.spt"</scriptWhenChecked> |
| - | Little is known about how substrates bind to CtXR (Candida tenuis xylose reductase; AKR2B5) and other members of the AKR (aldo-keto reductase) protein superfamily. Modelling of xylose into the active site of CtXR suggested that Trp23, Asp50 and Asn309 are the main components of pentose-specific substrate-binding recognition. Kinetic consequences of site-directed substitutions of these residues are reported. The mutants W23F and W23Y catalysed NADH-dependent reduction of xylose with only 4 and 1% of the wild-type efficiency (kcat/K(m)) respectively, but improved the wild-type selectivity for utilization of ketones, relative to xylose, by factors of 156 and 471 respectively. Comparison of multiple sequence alignment with reported specificities of AKR members emphasizes a conserved role of Trp23 in determining aldehyde-versus-ketone substrate selectivity. D50A showed 31 and 18% of the wild-type catalytic-centre activities for xylose reduction and xylitol oxidation respectively, consistent with a decrease in the rates of the chemical steps caused by the mutation, but no change in the apparent substrate binding constants and the pattern of substrate specificities. The 30-fold preference of the wild-type for D-galactose compared with 2-deoxy-D-galactose was lost completely in N309A and N309D mutants. Comparison of the 2.4 A (1 A=0.1 nm) X-ray crystal structure of mutant N309D bound to NAD+ with the previous structure of the wild-type holoenzyme reveals no major structural perturbations. The results suggest that replacement of Asn309 with alanine or aspartic acid disrupts the function of the original side chain in donating a hydrogen atom for bonding with the substrate C-2(R) hydroxy group, thus causing a loss of transition-state stabilization energy of 8-9 kJ/mol.
| + | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> |
| - | | + | <text>to colour the structure by Evolutionary Conservation</text> |
| - | ==About this Structure== | + | </jmolCheckbox> |
| - | 1Z9A is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Candida_tenuis Candida tenuis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1Z9A OCA].
| + | </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=1z9a ConSurf]. |
| - | | + | <div style="clear:both"></div> |
| - | ==Reference== | + | __TOC__ |
| - | Probing the substrate binding site of Candida tenuis xylose reductase (AKR2B5) with site-directed mutagenesis., Kratzer R, Leitgeb S, Wilson DK, Nidetzky B, Biochem J. 2006 Jan 1;393(Pt 1):51-8. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16336198 16336198]
| + | </StructureSection> |
| - | [[Category: Candida tenuis]] | + | [[Category: Large Structures]] |
| - | [[Category: Single protein]] | + | [[Category: Yamadazyma tenuis]] |
| - | [[Category: Kratzer, R.]] | + | [[Category: Kratzer R]] |
| - | [[Category: Leitgeb, S.]] | + | [[Category: Leitgeb S]] |
| - | [[Category: Nidetzky, B.]] | + | [[Category: Nidetzky B]] |
| - | [[Category: Wilson, D K.]] | + | [[Category: Wilson DK]] |
| - | [[Category: akr]]
| + | |
| - | [[Category: aldo-keto reductase]]
| + | |
| - | [[Category: beta-alpha-barrel]]
| + | |
| - | [[Category: candida tenui]]
| + | |
| - | [[Category: ketone reduction]]
| + | |
| - | [[Category: structure-activity correlation]]
| + | |
| - | [[Category: substrate selectivity]]
| + | |
| - | [[Category: xylose reductase]]
| + | |
| - | | + | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 01:32:32 2008''
| + | |
