Antitermination during the infection cycle of bacteriophageλ Genes N cro L1 nut PL P nutT Immediate-early transcripts Genes N cro CloP Q L1 nut P R nutR toa t R3 "Delayed-early" transcripts
Antitermination during the infection cycle of bacteriophage
Attenuation results in premature termination The coupling of transcription and translation is important in that it allows a special type of control, called attenuation s it the reason for the coupling? Another reason has been proposed
Attenuation results in premature termination • The coupling of transcription and translation is important in that it allows a special type of control, called attenuation. • Is it the reason for the coupling? Another reason has been proposed
The coupling of transcription and translation RNA polymerase Ribosome DNA RNA Protein
The coupling of transcription and translation
trpE trpD trpc trpB trpA DNA lE Attenuation Large hairpin at the loop OR tryptophan Short open Start of trpE Short open Start of reading frame reading frame trpE operon Termination signal Limiting amounts Adequate amounts of tryptophan of tryptophan RNA polymerase Ribosome RIBOSOME STALLS RIBOSOME DOES NOT STALL Large hairpin loop forms Termination signal forms Transcription continues Transcription terminates
Attenuation at the tryptophan operon
trpE DNA IE Regulation Large hairpin of the RNA OR tryptophan Start of trPE Bound Sta operon of of trpE TRAP Termination signal Bacillus subtilis Limiting amounts Adequate amounts of tryptophan of tryptophan RNA polymerase TRAP DOES NOT BIND TRAP BINDS Large hairpin loop forms Termination signal forms Transcription continues Transcription terminates
Regulation of the tryptophan operon of Bacillus subtilis