View source for 1eb8


==Structure Determinants of Substrate Specificity of Hydroxynitrile Lyase from Manihot esculenta==
<StructureSection load='1eb8' size='340' side='right'caption='[[1eb8]], [[Resolution|resolution]] 2.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1eb8]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Manihot_esculenta Manihot esculenta]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EB8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1EB8 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]] 2.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MPD:(4S)-2-METHYL-2,4-PENTANEDIOL'>MPD</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=1eb8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1eb8 OCA], [https://pdbe.org/1eb8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1eb8 RCSB], [https://www.ebi.ac.uk/pdbsum/1eb8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1eb8 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HNL_MANES HNL_MANES] Involved in cyanogenesis, the release of HCN from injured tissues. Decomposes a varieties of (R) or (S) cyanohydrins into HCN and the corresponding aldehydes and ketones. The natural substrate of this enzyme is (S)-acetone cyanohydrin.
== 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/eb/1eb8_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=1eb8 ConSurf].
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== Publication Abstract from PubMed ==
Tryptophan 128 of hydroxynitrile lyase of Manihot esculenta (MeHNL) covers a significant part of a hydrophobic channel that gives access to the active site of the enzyme. This residue was therefore substituted in the mutant MeHNL-W128A by alanine to study its importance for the substrate specificity of the enzyme. Wild-type MeHNL and MeHNL-W128A showed comparable activity on the natural substrate acetone cyanohydrin (53 and 40 U/mg, respectively). However, the specific activities of MeHNL-W128A for the unnatural substrates mandelonitrile and 4-hydroxymandelonitrile are increased 9-fold and approximately 450-fold, respectively, compared with the wild-type MeHNL. The crystal structure of the MeHNL-W128A substrate-free form at 2.1 A resolution indicates that the W128A substitution has significantly enlarged the active-site channel entrance, and thereby explains the observed changes in substrate specificity for bulky substrates. Surprisingly, the MeHNL-W128A--4-hydroxybenzaldehyde complex structure at 2.1 A resolution shows the presence of two hydroxybenzaldehyde molecules in a sandwich type arrangement in the active site with an additional hydrogen bridge to the reacting center.

Structure determinants of substrate specificity of hydroxynitrile lyase from Manihot esculenta.,Lauble H, Miehlich B, Forster S, Kobler C, Wajant H, Effenberger F Protein Sci. 2002 Jan;11(1):65-71. PMID:11742123<ref>PMID:11742123</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Manihot esculenta]]
[[Category: Effenberger F]]
[[Category: Foerster S]]
[[Category: Kobler C]]
[[Category: Lauble H]]
[[Category: Miehlich B]]
[[Category: Wajant H]]