title: Chemical modification of PABA synthase.
abstract: p-Aminobenzoic acid (PABA) synthase catalyses the first step in folic acid biosynthesis, the conversion of chorismate to p-aminobenzoate. In general, difficulties in purification have permitted only limited investigation of this enzyme. However, in an attempt to identify possible active site residues, the E. coli enzyme has been incubated with a range of protein modifying agents. Results indicate that cysteine, histidine, arginine and tyrosine residues are important for enzyme activity. Attempts were made to determine the subunits upon which these residues were located.
authors.affiliation: School of Pharmaceutical Chemistry, Victorian College of Pharmacy (Monash University) Ltd., Parkville.
authors.forename: M J
authors.initials: MJ
authors.lastname: McLeish
authors.forename: J M
authors.initials: JM
authors.lastname: Caine
mesh_terms: D001120:Arginine / Q000737:chemistry; D003545:Cysteine / Q000737:chemistry; D004047:Diethyl Pyrocarbonate / Q000494:pharmacology; D004926:Escherichia coli / Q000201:enzymology*; D005492:Folic Acid / Q000096:biosynthesis; D006639:Histidine / Q000737:chemistry; D007460:Iodoacetamide / Q000494:pharmacology; D010658:Phenylglyoxal / Q000494:pharmacology; D013439:Sulfhydryl Reagents / Q000494:pharmacology; D013774:Tetranitromethane / Q000494:pharmacology; D000637:Transaminases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D014443:Tyrosine / Q000737:chemistry
chemical_list: D013439:Sulfhydryl Reagents; D014443:Tyrosine; D006639:Histidine; D005492:Folic Acid; D001120:Arginine; C022309:PABA synthase; D000637:Transaminases; D013774:Tetranitromethane; D003545:Cysteine; D004047:Diethyl Pyrocarbonate; D010658:Phenylglyoxal; D007460:Iodoacetamide