Question

if you are a bacterial cell, list two things that you can do to counter the antibiotic rifampicin.

Answer 1

Ans.

Antibiotic rifampicin binds to the RNA polymerase β subunit and thus inhibit the transcription of bacterial gene.

Two things that can be done to counter the antibiotic rifampicin, are as follows:

1. Chemical modification of the antibiotic by the bacterial enzyme thus inactivating the antibiotic.

e.g. There is an enzyme called Arr that catalyze ADP-ribosylation of rifamycins. In this the ADP-ribose group is added to the rifamycins thereby inactivating it. Due to this chemical modification, rifamycins cannot bind to RNA polymerase and inhibit its activity.

2. Mutating the RNA polymerase β (rpoB) gene of bacteria in such a way that its product (RNA polymerase β subunit) can no longer bind to rifampicin. In this way rifampicin cannot inhibit the activity of RNA polymerase.