Corrigendum: Gene Expression in Class 2 Integrons Is SOS-Independent and Involves Two Pc Promoters.

[This corrects the article on p. 1499 in vol. 8, PMID: 28861047.

Gene Expression in Class 2 Integrons Is SOS-Independent and Involves Two Pc Promoters.

Integrons are powerful bacterial genetic elements that permit the expression and dissemination of antibiotic-resistance gene cassettes. They contain a promoter Pc that allows the expression of gene cassettes captured through site-specific recombination catalyzed by IntI, the integron-encoded integrase. Class 1 and 2 integrons are found in both clinical and environmental settings.

Expression of the Gene in Class 1 Integrons.

is a plasmid-mediated quinolone resistance gene embedded within a gene cassette, most often within an integron. It confers resistance to quinolones and aminoglycosides. We investigated the role of a 101-bp fragment frequently present upstream of the gene cassette and found that it contributes to the expression of and provides an alternative start codon, confirming the length of the AAC(6')-Ib-cr protein to 199 amino acids.

High-level gene cassette transcription prevents integrase expression in class 1 integrons.

Class 1 integrons are widespread genetic elements responsible for dissemination of antibiotic resistance among Gram-negative bacteria. Integrons allow bacteria to capture and express gene cassettes (GCs) via an integrase (IntI1) and a promoter (Pc) contained in the integron functional platform. GCs are transcribed from Pc, of which 13 variants of different strengths have been described, or, occasionally, from both Pc and a second promoter (P2).