Pabarcus_2002_Biochim.Biophys.Acta_1596_201

Reference

Title : Kynurenine formamidase: determination of primary structure and modeling-based prediction of tertiary structure and catalytic triad - Pabarcus_2002_Biochim.Biophys.Acta_1596_201
Author(s) : Pabarcus MK , Casida JE
Ref : Biochimica & Biophysica Acta , 1596 :201 , 2002
Abstract :

Kynurenine formamidase (KFase) (EC 3.5.1.9) hydrolyzes N-formyl-L-kynurenine, an obligatory step in the conversion of tryptophan to nicotinic acid. Low KFase activity in chicken embryos, from inhibition by organophosphorus insecticides and their metabolites such as diazoxon, leads to marked developmental abnormalities. While KFase was purportedly isolated previously, the structure and residues important for catalysis and inhibition were not established. KFase was isolated here from mouse liver cytosol by (NH4)2SO4 precipitation and three FPLC steps (resulting in 221-fold increase in specific activity for N-formyl-L-kynurenine hydrolysis) followed by conversion to [3H]diethylphosphoryl-KFase and finally isolation by C4 reverse-phase high-performance liquid chromatography. Determination of tryptic fragment amino acid sequences and cDNA cloning produced a new 305-amino-acid protein sequence. Although an amidase by function, the primary structure of KFase lacks the amidase signature sequence and is more similar to esterases and lipases. Sequence profile analysis indicates KFase is related to the esterase/lipase/thioesterase family containing the conserved active-site serine sequence GXSXG. The alpha/beta-hydrolase fold is suggested for KFase by its primary sequence and predicted secondary conformation. A three-dimensional model based on the structures of homologous carboxylesterase EST2 and brefeldin A esterase implicates Ser162, Asp247 and His279 as the active site triad.

PubMedSearch : Pabarcus_2002_Biochim.Biophys.Acta_1596_201
PubMedID: 12007602
Gene_locus related to this paper: human-AFMID , mouse-KFA

Related information

Gene_locus human-AFMID    mouse-KFA

Citations formats

Pabarcus MK, Casida JE (2002)
Kynurenine formamidase: determination of primary structure and modeling-based prediction of tertiary structure and catalytic triad
Biochimica & Biophysica Acta 1596 :201

Pabarcus MK, Casida JE (2002)
Biochimica & Biophysica Acta 1596 :201