Regulation of Bacteriophage Entry into the Lytic or Lysogenic Cycle

o N is produced by transcription from Pl. 0 Transcription from P,z produces Cro l l mRNA- mRNA- antiterminator to extend l e N protein acts as an transcription beyond termination sequences t1, t“, and t”. N protein é {a Q 0 Accumulation of clll protein cll protein Cro protein Cro protein a Accumulation of cll/clll complex leads to lysogenic cycle. , d d k . . Cro an )i repressor un erta e Lysogemc cycle development competitive binding for operators Om, O”, and OM. cll/clll protein P1cIII m E 0 cll/clll binding to PL 9 cll/clll binding to PM, leads leads to expression to expression of cl, the A of integrase that can repressor protein. stimulate prophage integration. A repressor , . , . protein Lysogenic cycle if Lytic cycle if Cro A repressor binds binds to o,” to 0R1 and 0R2 G Transcription occurs from PM to transcribe cl, and transcription from P,( is blocked. The lysogenic cycle is established. eTranscription continues from PL and P and delayed early and late gene transcription lea s to the lytic cycle,