Lauble_2001_Protein.Sci_10_1015

Reference

Title : Mechanistic aspects of cyanogenesis from active-site mutant Ser80Ala of hydroxynitrile lyase from Manihot esculenta in complex with acetone cyanohydrin - Lauble_2001_Protein.Sci_10_1015
Author(s) : Lauble H , Miehlich B , Forster S , Wajant H , Effenberger F
Ref : Protein Science , 10 :1015 , 2001
Abstract :

The structure and function of hydroxynitrile lyase from Manihot esculenta (MeHNL) have been analyzed by X-ray crystallography and site-directed mutagenesis. The crystal structure of the MeHNL-S80A mutant enzyme has been refined to an R-factor of 18.0% against diffraction data to 2.1-A resolution. The three-dimensional structure of the MeHNL-S80A-acetone cyanohydrin complex was determined at 2.2-A resolution and refined to an R-factor of 18.7%. Thr11 and Cys81 involved in substrate binding have been substituted by Ala in site-directed mutagenesis. The kinetic measurements of these mutant enzymes are presented. Combined with structural data, the results support a mechanism for cyanogenesis in which His236 as a general base abstracts a proton from Ser80, thereby allowing proton transfer from the hydroxyl group of acetone cyanohydrin to Ser80. The His236 imidazolium cation then facilitates the leaving of the nitrile group by proton donating.

PubMedSearch : Lauble_2001_Protein.Sci_10_1015
PubMedID: 11316882
Gene_locus related to this paper: manes-hnl

Related information

Gene_locus manes-hnl
Structure manes-hnl    1E89

Citations formats

Lauble H, Miehlich B, Forster S, Wajant H, Effenberger F (2001)
Mechanistic aspects of cyanogenesis from active-site mutant Ser80Ala of hydroxynitrile lyase from Manihot esculenta in complex with acetone cyanohydrin
Protein Science 10 :1015

Lauble H, Miehlich B, Forster S, Wajant H, Effenberger F (2001)
Protein Science 10 :1015