Amino Acid Sequence, Aspartate Carbamoyltransferase, Base Sequence, DNA-Directed RNA Polymerases, Escherichia coli, Guanylyl Imidodiphosphate, Heparin, Kinetics, Molecular Sequence Data, Operon, Plasmids, Potassium Chloride, Promoter Regions, Genetic, Pyrimidines, RNA, Bacterial, Restriction Mapping, Transcription, Genetic