Functional Characterization of a Cassette-Specific Promoter in the Class 1 Integron-AssociatedqnrVC1Gene

Abstract

ABSTRACTIntegrons are natural expression vectors due to the presence of an intrinsic promoter (Pc). Although rare, gene cassettes can harbor their own promoter. This study determined the functionality of an internal promoter in theqnrVC1cassette whose presence was suggested by a level of transcription similar to that of the preceding cassette (aadA2) and confirmed byin silicoanalysis. Its functionality was determined by 5′ rapid amplification of cDNA ends (RACE) and cloning into promoter-probe vectors. PqnrVCwas found in theqnrVCcassette family, stressing its role in contributing to resistance manifestation.