title: Isolation of uracil auxotrophs from Burkholderia cepacia ATCC 25416.
abstract: Two uracil auxotrophs of the phytopathogen Burkolderia cepacia ATCC 25416, which is known to be involved in food spoilage, were isolated by a combination of ethylmethane sulphonate and D-cycloserine counterselection. One mutant exhibited depressed orotate phosphoribosyltransferase activity while the other mutant lacked orotidine 5'-monophosphate decarboxylase activity. Pyrimidine limitation of either auxotroph elevated aspartate transcarbamoylase and dihydroorotase activities by at least 1:5-fold indicating that these pathway enzymes may be repressible by a uracil-related compound in B. cepacia. Overall, regulation of de novo pyrimidine synthesis in the uracil auxotrophs of B. cepacia ATCC 25416 was observed.
authors.affiliation: Olson Biochemistry Laboratories, Department of Chemistry and Biochemistry, South Dakota State University, Brookings, USA.
authors.forename: K
authors.initials: K
authors.lastname: Li
authors.forename: T P
authors.initials: TP
authors.lastname: West
mesh_terms: D001221:Aspartate Carbamoyltransferase / Q000378:metabolism; D016956:Burkholderia cepacia / Q000201:enzymology / Q000378:metabolism*; D003523:Cycloserine / Q000378:metabolism; D004080:Dihydroorotase / Q000378:metabolism; D005020:Ethyl Methanesulfonate; D016296:Mutagenesis; D009962:Orotate Phosphoribosyltransferase / Q000378:metabolism; D009964:Orotidine-5'-Phosphate Decarboxylase / Q000378:metabolism; D011742:Pyrimidine Nucleotides / Q000378:metabolism; D011743:Pyrimidines / Q000096:biosynthesis; D014498:Uracil / Q000378:metabolism*
chemical_list: D011742:Pyrimidine Nucleotides; D011743:Pyrimidines; D014498:Uracil; D003523:Cycloserine; D005020:Ethyl Methanesulfonate; D001221:Aspartate Carbamoyltransferase; D009962:Orotate Phosphoribosyltransferase; D004080:Dihydroorotase; D009964:Orotidine-5'-Phosphate Decarboxylase; C030986:pyrimidine