Question

Recent structural models show that a poison inhibits translation by binding to a site inside RNA polymerase but not to the active site. Based on the model of bacterial RNA polymerase, predict where this poison binds and why it inhibits transcription.

Answer 1

Ans:- this poison would bind to back of RNA polymerase at bridge helix of enzyme which is not active site where DNA or RNA binds hence it would not block active site. but instead binding between two subunit of RNA polymerase it jam movement of enzyme and interfere with translocation of RNA and DNA. RNA polymerase is highly mobile enzyme as it is involved in unwinding of DNA and synthesis of RNA. it changes its shapes while transcription which get blocked by poison and inhibit transcription. example of this poison is alpha-amanitin