The aliphatic amidase from Pseudomonas aeruginosa belongs to the nitrilase superfamily, and Cys(166) is the nucleophile of the catalytic mechanism. A model of amidase was built by comparative modelling using the crystal structure of the worm nitrilase-fragile histidine triad fusion protein (NitFhit; Protein Data Bank accession number 1EMS) as a template. The amidase model predicted a catalytic triad (Cys-Glu-Lys) situated at the bottom of a pocket and identical with the presumptive catalytic triad of NitFhit. Three-dimensional models for other amidases belonging to the nitrilase superfamily also predicted Cys-Glu-Lys catalytic triads. Support for the structure for the P. aeruginosa amidase came from site-direct mutagenesis and from the locations of amino acid residues that altered substrate specificity or binding when mutated.
Support for a three-dimensional structure predicting a Cys-Glu-Lys catalytic triad for Pseudomonas aeruginosa amidase comes from site-directed mutagenesis and mutations altering substrate specificity.,Novo C, Farnaud S, Tata R, Clemente A, Brown PR Biochem J. 2002 Aug 1;365(Pt 3):731-8. PMID:11955282[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
↑ Novo C, Farnaud S, Tata R, Clemente A, Brown PR. Support for a three-dimensional structure predicting a Cys-Glu-Lys catalytic triad for Pseudomonas aeruginosa amidase comes from site-directed mutagenesis and mutations altering substrate specificity. Biochem J. 2002 Aug 1;365(Pt 3):731-8. PMID:11955282 doi:10.1042/BJ20011714
