title: Pyrimidine pools and macromolecular composition of pyrimidine-limited Escherichia coli.
abstract: The growth rate of a pyrimidine-requiring strain was controlled by limiting the concentration of exogenous orotic acid. As the steady state, pyrimidine-limited growth rate was decreased, the intracellular pyrimidine pools and the total nucleic acid per unit mass of culture also decreased. The ratio of deoxyribonucleic acid to protein remained constant, whereas the ratio of ribonucleic acid to protein decreased 30% over a threefold variation in growth rate (50- to 150-min doubling times). The intracellular uridine triphosphate and cytosine triphosphate pools also decreased (although not coordinately), and the pyrimidine biosynthetic enzymes were derepressed. Cell size was unaffected by pyrimidine-mediated variation of the growth rate.
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis* / Q000378:metabolism; D002247:Carbon Isotopes; D002498:Centrifugation; D002855:Chromatography, Thin Layer; D003470:Culture Media; D003597:Cytosine Nucleotides / Q000032:analysis; D004269:DNA, Bacterial / Q000032:analysis* / Q000378:metabolism; D004926:Escherichia coli / Q000032:analysis / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D009963:Orotic Acid / Q000494:pharmacology; D011743:Pyrimidines / Q000096:biosynthesis*; D012329:RNA, Bacterial / Q000032:analysis* / Q000378:metabolism; D014166:Transferases / Q000378:metabolism; D014238:Trichloroacetic Acid; D014498:Uracil / Q000494:pharmacology; D014500:Uracil Nucleotides / Q000032:analysis / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002247:Carbon Isotopes; D003470:Culture Media; D003597:Cytosine Nucleotides; D004269:DNA, Bacterial; D011743:Pyrimidines; D012329:RNA, Bacterial; D014500:Uracil Nucleotides; D014498:Uracil; D014238:Trichloroacetic Acid; D009963:Orotic Acid; D014166:Transferases