上游充通大淫 SHANGHAI JIAO TONG UNIVERSITY arg Promoterarg Operator argc argB argH RNA polymerase →→→ Transcription proceeds (a) Repressor arg Promoter)arg Operator argc argB argH RNA Corepressor polymerase (arginine) Transcription blocked (b) Repressor 2012 Pearson Education.Inc. The process of enzyme repressionThe process of enzyme repression Chen Feng, Shanghai Jiao Tong University