Question

In an experiment you wrongly added Rifampicin antibiotic to Rifampicin sensitive bacteria. You try to correct your mistake by adding more core subunits (resistant to Rifampicin) to your mixture. What would you expect to see?

(a) Normal transcription to restart

(b) Transcription will restart but it will be non-specific as you added core enzyme

(c) Impaired transcription with more abortive transcripts

(d) No transcription

The question was posed to me during an interview.

The above asked question is from Transcription in Prokaryotes : Sigma Factor in division Gene Expression : Transcription Prokaryotes of Cytogenetics

Answer 1

Right choice is (a) Normal transcription to restart

The best I can explain: The sigma factor is not affected by Rifampicin and it is dissociable. The sigma already present in mixture will add to the Rifampicin resistant core and restore normal transcription of specific genes. No increased abortive transcription will be seen.