pyrophosphate and pyrimidine

The control of pyrimidine nucleotide formation in the bacterium Pseudomonas aurantiaca ATCC 33663 by pyrimidines was studied. The activities of the pyrimidine biosynthetic pathway enzymes were investigated in P. aurantiaca ATCC 33663 cells and from cells of an auxotroph lacking orotate phosphoribosyltransferase activity under selected culture conditions. All activities of the pyrimidine biosynthetic pathway enzymes in ATCC 33663 cells were depressed by uracil addition to the minimal medium when succinate served as the carbon source. In contrast, all pyrimidine biosynthetic pathway enzyme activities in ATCC 33663 cells were depressed by orotic acid supplementation to the minimal medium when glucose served as the carbon source. The orotidine 5'-monophosphate decarboxylase activity in the phosphoribosyltransferase mutant strain increased by more than sixfold in succinate-grown cells and by more than 16-fold in glucose-grown cells after pyrimidine limitation showing possible repression of the decarboxylase by a pyrimidine-related compound. Inhibition by ATP, GTP, UTP and pyrophosphate of the in vitro activity of aspartate transcarbamoylase in ATCC 33663 was observed. The findings demonstrated control at the level of pyrimidine biosynthetic enzyme synthesis and activity for the P. aurantiaca transcarbamoylase. The control of pyrimidine synthesis in P. aurantiaca seemed to differ from what has been observed previously for the regulation of pyrimidine biosynthesis in related Pseudomonas species. This investigation could prove helpful to future work studying pseudomonad taxonomic analysis as well as to those exploring antifungal and antimicrobial agents produced by P. aurantiaca.

Topics: Aspartate Carbamoyltransferase; Biosynthetic Pathways; Diphosphates; Gene Expression Regulation, Bacterial; Orotate Phosphoribosyltransferase; Orotidine-5'-Phosphate Decarboxylase; Pseudomonas; Pyrimidine Nucleotides; Pyrimidines; Succinic Acid; Uracil

The control of de novo pyrimidine biosynthesis in the industrially important patent strain "Pseudomonas alkanolytica" ATCC 21034 was investigated. Uracil supplementation of succinate-grown "P. alkanolytica" cells produced the greatest depression of the de novo pyrimidine biosynthetic pathway enzyme activities. After the pyrimidine limitation of a "P. alkanolytica" orotate phosphoribosyltransferase mutant strain grown on succinate, the pyrimidine biosynthetic pathway enzyme activities were derepressed. The pyrimidine biosynthetic pathway enzyme aspartate transcarbamoylase in "P. alkanolytica" was inhibited by pyrophosphate, cytidine 5'-triphosphate (CTP), uridine 5'-triphosphate (UTP), and guanosine 5'-triphosphate (GTP).

Topics: Aspartate Carbamoyltransferase; Cytidine Triphosphate; Diphosphates; Enzyme Repression; Gene Expression Regulation, Bacterial; Genes, Bacterial; Guanosine Triphosphate; Mutation; Orotate Phosphoribosyltransferase; Pseudomonas; Pyrimidines; Succinic Acid; Uracil; Uridine Triphosphate

Pyrimidine synthesis in the food spoilage agent Burkholderia cepacia ATCC 25416 was investigated. The five de novo pathway enzymes of pyrimidine biosynthesis were found to be active in B. cepacia ATCC 25416 and growth of this strain on uracil had an effect on the de novo enzyme activities. The in vitro regulation of aspartate transcarbamoylase activity in B. cepacia ATCC 25416 was studies and its activity was inhibited by PP(i), ATP, GTP, CTP and UTP. The enzymes cytidine deaminase, uridine phosphorylase and cytosine deaminase were found to be active in the salvage of pyrimidines in ATCC 25416. Overall, de novo pyrimidine synthesis in B. cepacia ATCC 25416 was regulated at the level of enzyme activity and its pyrimidine salvage enzymes differed from those found in B. cepacia ATCC 17759.

Topics: Aspartate Carbamoyltransferase; Burkholderia cepacia; Cytidine Deaminase; Cytosine Deaminase; Diphosphates; Enzyme Inhibitors; Nucleoside Deaminases; Nucleotides; Pyrimidines; Uracil; Uridine Phosphorylase

Topics: Adenine; Adenine Nucleotides; Animals; Carbon Isotopes; Chromatography; Cytosine; Cytosine Nucleotides; Diphosphates; Fishes; Guanine; Guanine Nucleotides; Metabolism; Nucleotides; Orotic Acid; Phosphoribosyl Pyrophosphate; Purines; Pyrimidines; Research; Salmon; Thymine; Tissue Extracts; Tritium; Uracil; Uracil Nucleotides; Xanthines

Topics: Deoxyribonucleosides; Diphosphates; Escherichia coli; Nucleosides; Nucleotides; Pyrimidines

Topics: Biochemical Phenomena; Diphosphates; Enzymes; Phosphates; Pyrimidines; Thiamine; Thiazoles

Topics: Diphosphates; Nucleic Acids; Pyrimidines; RNA; Snake Venoms

Topics: Diphosphates; Esterases; Nucleic Acids; Nucleotides; Phosphoric Diester Hydrolases; Pyrimidines; RNA