DNA sequences for CAP, RNA polymerase and lac-repressor
Entire DNA segment has been sequenced from transcription termination (downstream) end of 'lac I' gene to beyond the transcription start of Z, Y, A genes of lac operon. This sequence contains the promoter and operator segments. Different parts of this sequence have been studied for their functions. For instance, sequences of three binding sites for CAP, RNA polymerase enzyme and 'lac' repressor could be identified through the technique of DNA footprinting. These sequences are shown in Fig. 35.21.