pyrophosphate and anthranilic-acid

Anthranilate phosphoribosyltransferase (AnPRT) catalyzes the transfer of the phosphoribosyl group of 5'-phosphoribosyl-1'-pyrophosphate (PRPP) to anthranilate to form phosphoribosyl-anthranilate. Crystal structures of AnPRTs from bacteria and archaea have previously been determined; however, the structure of Saccharomyces cerevisiae AnPRT (ScAnPRT) still remains unsolved. Here, crystal structures of ScAnPRT in the apo form as well as in complex with its substrate PRPP and the substrate analogue 4-fluoroanthranilate (4FA) are presented. These structures demonstrate that ScAnPRT exhibits the conserved structural fold of type III phosphoribosyltransferase enzymes and shares the similar mode of substrate binding found across the AnPRT protein family. In addition, crystal structures of ScAnPRT mutants (ScAnPRT

Topics: Amino Acid Motifs; Amino Acid Sequence; Anthranilate Phosphoribosyltransferase; Binding Sites; Conserved Sequence; Crystallography, X-Ray; Diphosphates; ortho-Aminobenzoates; Protein Multimerization; Protein Structure, Secondary; Saccharomyces cerevisiae

Extracts of livers from diabetic rats contain normal amounts of the enzymes needed to convert 3-hydroxyanthranilic acid to nicotinic acid nucleotide. The decreased capacity of diabetic animals to synthesize nicotinic acid is therefore attributed to increased amounts of picolinic carboxylase, which competes for a common intermediate with the spontaneous reaction in which quinolinic acid is formed as a precursor of nicotinic acid. These studies were facilitated by the synthesis of 3-hydroxyanthranilic acid labeled with carbon-14 in positions 3 and 6

Topics: Adenosine Triphosphate; Animals; Carbon Dioxide; Carbon Isotopes; Carbon Radioisotopes; Carboxy-Lyases; Diabetes Mellitus, Experimental; Diphosphates; Liver; Liver Extracts; Manometry; Metabolism; Niacin; Nicotinic Acids; ortho-Aminobenzoates; Oxidoreductases; Pharmacology; Pyridines; Rats; Research