targeted_by targeted_by_antibiotic targeted_by targeted_by_antibiotic nucleic acid synthesis machinery targeted by antibiotic macrocyclic antibiotic fidaxomicin antibiotic sensitive RNA polymerase switch region The switch region is a structural element that mediates conformational changes and contacts required for RNAP to load DNA into the RNAP active-center cleft during transcription initiation. The switch region is located at the base of the RNAP clamp and serves as the hinge that mediates opening of the RNAP clamp to load DNA into the RNAP active-center cleft and mediates closing of the RNAP clamp to retain DNA in the RNAP active-center cleft. ARO:3003439 antibiotic_resistance