title: Control of pyrimidine formation in Pseudomonas putida ATCC 17536.
abstract: The regulation of de novo pyrimidine biosynthesis in Pseudomonas putida ATCC 17536 by pyrimidines was explored. The pathway enzyme activities were higher in glucose-grown cells than in succinate-grown cells, indicating catabolite repression by succinate. In P. putida cells grown on succinate as a carbon source, only aspartate transcarbamoylase activity was greatly diminished by uracil supplementation. When glucose was the carbon source, orotic acid supplementation significantly decreased orotate phosphoribosyltransferase and orotidine 5'-monophosphate (OMP) decarboxylase activities. Uracil auxotrophs, deficient for dihydroorotase activity or with reduced phosphoribosyltransferase activity, were isolated. After pyrimidine limitation of both auxotrophs, the greatest derepression of enzyme activity was observed for OMP decarboxylase independent of carbon source. Orotic acid induced both phosphoribosyltransferase and decarboxylase activities in glucose-grown cells of the dihydroorotase-deficient strain. Regulation at the transcriptional level of de novo pyrimidine biosynthetic enzyme synthesis in P. putida ATCC 17536 was observed, which contrasts with previous observations.
authors.affiliation: Olson Biochemistry Laboratories, Department of Chemistry and Biochemistry, South Dakota State University, Brookings, SD 57007, USA.
authors.forename: Manuel F
authors.initials: MF
authors.lastname: Santiago
authors.forename: Thomas P
authors.initials: TP
authors.lastname: West
mesh_terms: D001221:Aspartate Carbamoyltransferase / Q000032:analysis / Q000378:metabolism; D004080:Dihydroorotase / Q000032:analysis / Q000378:metabolism; D000090722:Dihydroorotate Dehydrogenase; D005947:Glucose / Q000378:metabolism; D009962:Orotate Phosphoribosyltransferase / Q000032:analysis / Q000378:metabolism; D009964:Orotidine-5'-Phosphate Decarboxylase / Q000032:analysis / Q000378:metabolism; D010088:Oxidoreductases / Q000032:analysis / Q000378:metabolism; D044925:Oxidoreductases Acting on CH-CH Group Donors; D016958:Pseudomonas putida / Q000201:enzymology / Q000378:metabolism*; D011743:Pyrimidines / Q000096:biosynthesis*; D019802:Succinic Acid / Q000378:metabolism
chemical_list: D000090722:Dihydroorotate Dehydrogenase; D011743:Pyrimidines; D019802:Succinic Acid; D010088:Oxidoreductases; D044925:Oxidoreductases Acting on CH-CH Group Donors; D001221:Aspartate Carbamoyltransferase; D009962:Orotate Phosphoribosyltransferase; D004080:Dihydroorotase; D009964:Orotidine-5'-Phosphate Decarboxylase; D005947:Glucose; C030986:pyrimidine