2vss: Difference between revisions
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[[Category: Pseudomonas fluorescens]] | [[Category: Pseudomonas fluorescens]] | ||
[[Category: Trans-feruloyl-CoA hydratase]] | [[Category: Trans-feruloyl-CoA hydratase]] | ||
[[Category: Bennett, J P | [[Category: Bennett, J P]] | ||
[[Category: Bertin, L M | [[Category: Bertin, L M]] | ||
[[Category: Brzozowski, A M | [[Category: Brzozowski, A M]] | ||
[[Category: Grogan, G | [[Category: Grogan, G]] | ||
[[Category: Walton, N J | [[Category: Walton, N J]] | ||
[[Category: Aldolase]] | [[Category: Aldolase]] | ||
[[Category: Crotonase]] | [[Category: Crotonase]] | ||
[[Category: Hydratase]] | [[Category: Hydratase]] | ||
[[Category: Lyase]] | [[Category: Lyase]] |
Revision as of 21:40, 19 January 2015
WILD-TYPE HYDROXYCINNAMOYL-COA HYDRATASE LYASE IN COMPLEX WITH ACETYL-COA AND VANILLINWILD-TYPE HYDROXYCINNAMOYL-COA HYDRATASE LYASE IN COMPLEX WITH ACETYL-COA AND VANILLIN
Structural highlights
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 PubMedHCHL (hydroxycinnamoyl-CoA hydratase-lyase) catalyses the biotransformation of feruloyl-CoA to acetyl-CoA and the important flavour-fragrance compound vanillin (4-hydroxy-3-methoxybenzaldehyde) and is exploited in whole-cell systems for the bioconversion of ferulic acid into natural equivalent vanillin. The reaction catalysed by HCHL has been thought to proceed by a two-step process involving first the hydration of the double bond of feruloyl-CoA and then the cleavage of the resultant beta-hydroxy thioester by retro-aldol reaction to yield the products. Kinetic analysis of active-site residues identified using the crystal structure of HCHL revealed that while Glu-143 was essential for activity, Ser-123 played no major role in catalysis. However, mutation of Tyr-239 to Phe greatly increased the K(M) for the substrate ferulic acid, fulfilling its anticipated role as a factor in substrate binding. Structures of WT (wild-type) HCHL and of the S123A mutant, each of which had been co-crystallized with feruloyl-CoA, reveal a subtle helix movement upon ligand binding, the consequence of which is to bring the phenolic hydroxyl of Tyr-239 into close proximity to Tyr-75 from a neighbouring subunit in order to bind the phenolic hydroxyl of the product vanillin, for which electron density was observed. The active-site residues of ligand-bound HCHL display a remarkable three-dimensional overlap with those of a structurally unrelated enzyme, vanillyl alcohol oxidase, that also recognizes p-hydroxylated aromatic substrates related to vanillin. The data both explain the observed substrate specificity of HCHL for p-hydroxylated cinnamate derivatives and illustrate a remarkable convergence of the molecular determinants of ligand recognition between the two otherwise unrelated enzymes. A ternary complex of hydroxycinnamoyl-CoA hydratase-lyase (HCHL) with acetyl-CoA and vanillin gives insights into substrate specificity and mechanism.,Bennett JP, Bertin L, Moulton B, Fairlamb IJ, Brzozowski AM, Walton NJ, Grogan G Biochem J. 2008 Sep 1;414(2):281-9. PMID:18479250[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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