title: Cloning, sequencing, and enhanced expression of the dihydropteroate synthase gene of Escherichia coli MC4100.
abstract: The Escherichia coli gene coding for dihydropteroate synthase (DHPS) has been cloned and sequenced. The protein has 282 amino acids and a compositional molecular mass of 30,314 daltons. Increased expression of the enzyme was realized by using a T7 expression system. The enzyme was purified and crystallized. A temperature-sensitive mutant was isolated and found to express a DHPS with a lower specific activity and lower affinities for para-aminobenzoic acid and sulfathiazole. The allele had a point mutation that changed a phenylalanine codon to a leucine codon, and the mutation was in a codon that is conserved among published DHPS sequences.
authors.affiliation: Department of Molecular Genetics and Microbiology, Burroughs Wellcome Co., Research Triangle Park, North Carolina 27709.
authors.forename: W S
authors.initials: WS
authors.lastname: Dallas
authors.forename: J E
authors.initials: JE
authors.lastname: Gowen
authors.forename: P H
authors.initials: PH
authors.lastname: Ray
authors.forename: M J
authors.initials: MJ
authors.lastname: Cox
authors.forename: I K
authors.initials: IK
authors.lastname: Dev
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D004094:Dihydropteroate Synthase / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D015723:Gene Library; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009690:Nucleic Acid Conformation; D012333:RNA, Messenger; D011994:Recombinant Proteins / Q000096:biosynthesis*; D012689:Sequence Homology, Nucleic Acid
chemical_list: D012333:RNA, Messenger; D011994:Recombinant Proteins; D004094:Dihydropteroate Synthase