title: Initiation of in vitro mRNA synthesis from the wild-type lac promoter.
abstract: An in vitro transcription system, dependent on catabolite gene activator protein (CAP), utilizing a 200 base-pair restriction fragment, has been used to show that the initiation site of the wild-type Escherichia coli lac mRNA, and that of two mutants, 8d and ps, are identical to that previously reported for the CAP-independent promoter mutant UV5. Order of addition experiments are used to show that the binding of lac repressor to the operator is competitive with that of the RNA polymerase (nucleosidetriphosphate:RNA nucleotidyltransferase, EC 2.7.7.6) to the promoter, thus demonstrating functional overlap of the operator and promoter sites.
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D005809:Genes, Regulator; D007785:Lactose; D009876:Operon; D012329:RNA, Bacterial / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis*; D014158:Transcription, Genetic
chemical_list: D012329:RNA, Bacterial; D012333:RNA, Messenger; D012321:DNA-Directed RNA Polymerases; D007785:Lactose