2026-06-07T19:00:26Zhttps://docta.ucm.es/rest/oai/request
oai:docta.ucm.es:20.500.14352/451822023-08-25T13:15:17Zcom_20.500.14352_14col_20.500.14352_15
Docta Complutense author Cambray, Guillaume author Sanchez Alberola, Neus author Campoy, Susana author Guerin, Emilie author Da Re, Sandra author González Zorn, Bruno author Ploy, Marie-Cécile author Barbé, Jordi author Mazel, Didier author Erill, Ivan 2023-06-20T04:20:17Z 2023-06-20T04:20:17Z 2011-04-30 1759-8753 10.1186/1759-8753-2-6 https://hdl.handle.net/20.500.14352/45182 http://mobilednajournal.biomedcentral.com/articles/10.1186/1759-8753-2-6 BACKGROUND Integrons are found in hundreds of environmental bacterial species, but are mainly known as the agents responsible for the capture and spread of antibiotic-resistance determinants between Gram-negative pathogens. The SOS response is a regulatory network under control of the repressor protein LexA targeted at addressing DNA damage, thus promoting genetic variation in times of stress. We recently reported a direct link between the SOS response and the expression of integron integrases in Vibrio cholerae and a plasmid-borne class 1 mobile integron. SOS regulation enhances cassette swapping and capture in stressful conditions, while freezing the integron in steady environments. We conducted a systematic study of available integron integrase promoter sequences to analyze the extent of this relationship across the Bacteria domain. RESULTS Our results showed that LexA controls the expression of a large fraction of integron integrases by binding to Escherichia coli-like LexA binding sites. In addition, the results provide experimental validation of LexA control of the integrase gene for another Vibrio chromosomal integron and for a multiresistance plasmid harboring two integrons. There was a significant correlation between lack of LexA control and predicted inactivation of integrase genes, even though experimental evidence also indicates that LexA regulation may be lost to enhance expression of integron cassettes. CONCLUSIONS Ancestral-state reconstruction on an integron integrase phylogeny led us to conclude that the ancestral integron was already regulated by LexA. The data also indicated that SOS regulation has been actively preserved in mobile integrons and large chromosomal integrons, suggesting that unregulated integrase activity is selected against. Nonetheless, additional adaptations have probably arisen to cope with unregulated integrase activity. Identifying them may be fundamental in deciphering the uneven distribution of integrons in the Bacteria domain. eng Atribución 3.0 España Prevalence of SOS-mediated control of integron integrase expression as an adaptive trait of chromosomal and mobile integrons journal article URL https://docta.ucm.es/bitstreams/a4f8b340-0d5b-48e0-be13-13ef19228eef/download File MD5 204e94a4c036947d115050ca72f8149f 5147513 application/pdf 426.pdf URL https://docta.ucm.es/bitstreams/a5245e86-fc83-4013-9b9d-0f80584bd119/download File MD5 b407871dd6d75d04b693e2fdb2a7b469 107266 text/plain 426.pdf.txt