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1yas

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Revision as of 06:56, 25 April 2018

HYDROXYNITRILE LYASE COMPLEXED WITH HISTIDINE

Structural highlights

1yas is a 1 chain structure with sequence from Hevbr. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	,
Gene:	HNL (HEVBR)
Activity:	Lyase, with EC number and 4.1.2.47 4.1.2.46 and 4.1.2.47
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[HNL_HEVBR] 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

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

BACKGROUND: Over three thousand species of plants, including important food crops such as cassava, use cyanogenesis, the liberation of HCN upon tissue damage, as a defense against predation. Detoxification of cyanogenic food crops requires disruption of the cyanogenic pathway. Hydroxynitrile lyase is one of the key enzymes in cyanogenesis, catalyzing the decomposition of an alpha-cyanohydrin to form HCN plus the corresponding aldehyde or ketone. These enzymes are also of potential utility for industrial syntheses of optically pure chiral cyanohydrins, being used to catalyze the reverse reaction. We set out to gain insight into the catalytic mechanism of this important class of enzymes by determining the three-dimensional structure of hydroxynitrile lyase from the rubber tree, Hevea brasiliensis. RESULTS: The crystal structure of the enzyme has been determined to 1.9 A resolution. It belongs to the alpha/beta hydrolase superfamily, with an active site that is deeply buried within the protein and connected to the outside by a narrow tunnel. The catalytic triad is made up of Ser80, His235 and Asp207. By analogy with known mechanisms of other members of this superfamily, catalysis should involve an oxyanion hole formed by the main chain NH of Cys81 and the side chains of Cys81 and Thr11. Density attributed to a histidine molecule or ion is found in the active site. CONCLUSIONS: By analogy with other alpha/beta hydrolases, the reaction catalyzed by hydroxynitrile lyase involves a tetrahedral hemiketal or hemiacetal intermediate formed by nucleophilic attack of Ser80 on the substrate, stabilized by the oxyanion hole. The SH group of Cys81 is probably involved in proton transfer between the HCN and the hydroxynitrile OH. This mechanism is significantly different from the corresponding uncatalyzed solution reaction.

Mechanism of cyanogenesis: the crystal structure of hydroxynitrile lyase from Hevea brasiliensis.,Wagner UG, Hasslacher M, Griengl H, Schwab H, Kratky C Structure. 1996 Jul 15;4(7):811-22. PMID:8805565^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Wagner UG, Hasslacher M, Griengl H, Schwab H, Kratky C. Mechanism of cyanogenesis: the crystal structure of hydroxynitrile lyase from Hevea brasiliensis. Structure. 1996 Jul 15;4(7):811-22. PMID:8805565

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1yas"

@@ Line 1: / Line 1: @@
 ==HYDROXYNITRILE LYASE COMPLEXED WITH HISTIDINE==
 <StructureSection load='1yas' size='340' side='right' caption='[[1yas]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
@@ Line 6: / Line 7: @@
 <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">HNL ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=3981 HEVBR])</td></tr>
 <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Lyase Lyase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.2.46 and 4.1.2.47 4.1.2.46 and 4.1.2.47] </span></td></tr>
-<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1yas FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1yas OCA], [http://pdbe.org/1yas PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1yas RCSB], [http://www.ebi.ac.uk/pdbsum/1yas PDBsum]</span></td></tr>
+<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1yas FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1yas OCA], [http://pdbe.org/1yas PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1yas RCSB], [http://www.ebi.ac.uk/pdbsum/1yas PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1yas ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 14: / Line 15: @@
 Check<jmol>
   <jmolCheckbox>
-    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ya/1yas_consurf.spt"</scriptWhenChecked>
+    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ya/1yas_consurf.spt"</scriptWhenChecked>
     <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
     <text>to colour the structure by Evolutionary Conservation</text>

1yas

From Proteopedia

Revision as of 06:56, 25 April 2018

HYDROXYNITRILE LYASE COMPLEXED WITH HISTIDINE

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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