title: Identification and nucleotide sequence of a gene encoding 5'-phosphoribosylglycinamide transformylase in Escherichia coli K12.
abstract: 5'-Phosphoribosylglycinamide transformylase (EC 2.1.2.2), encoded by the purN gene of Escherichia coli, catalyzes the synthesis of 5'-phosphoribosylformylglycinamide from 5'-phosphoribosylglycinamide (GAR). The mature protein, as deduced from the purN structural gene sequence, contains 212 amino acid residues and has a calculated Mr of 23,241. The purN gene is located adjacent to and immediately downstream from the purM gene encoding 5'-phosphoribosyl-5-aminoimidazole (AIR) synthetase where the initiation codon for GAR transformylase overlaps the termination codon of AIR synthetase. Based on polarity studies, the expression of the purN gene originates from the purM control region and thus forms a purMN operon. The E. coli GAR transformylase shows greater homology to the GAR transformylase domain of the trifunctional Gart polypeptide of Drosophila than to the single GAR transformylase of Saccharomyces. Immediately downstream from the purN gene of the purMN operon is a region of dyad symmetry capable of forming a hairpin stem and loop structure characteristic of a rho-independent terminator.
authors.forename: J M
authors.initials: JM
authors.lastname: Smith
authors.forename: H A
authors.initials: HA
authors.lastname: Daum
mesh_terms: D000217:Acyltransferases / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019731:Carbon-Nitrogen Ligases; D003062:Codon; D004274:DNA, Recombinant; D004330:Drosophila / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D005786:Gene Expression Regulation; D005798:Genes, Bacterial; D019877:Hydroxymethyl and Formyl Transferases; D008025:Ligases / Q000235:genetics; D008970:Molecular Weight; D009876:Operon; D051026:Phosphoribosylglycinamide Formyltransferase; D010957:Plasmids; D012441:Saccharomyces cerevisiae / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid
chemical_list: D003062:Codon; D004274:DNA, Recombinant; D019877:Hydroxymethyl and Formyl Transferases; D051026:Phosphoribosylglycinamide Formyltransferase; D000217:Acyltransferases; D008025:Ligases; D019731:Carbon-Nitrogen Ligases; C022380:phosphoribosylaminoimidazole synthase