RT Journal Article
T1 Prevalence of SOS-mediated control of integron integrase expression as an adaptive trait of chromosomal and mobile integrons
A1 Cambray, Guillaume
A1 Sanchez Alberola, Neus
A1 Campoy, Susana
A1 Guerin, Emilie
A1 Da Re, Sandra
A1 González Zorn, Bruno
A1 Ploy, Marie-Cécile
A1 Barbé, Jordi
A1 Mazel, Didier
A1 Erill, Ivan
AB BACKGROUNDIntegrons 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.RESULTSOur 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.CONCLUSIONSAncestral-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.
PB BioMedCentral
SN 1759-8753
YR 2011
FD 2011-04-30
LK https://hdl.handle.net/20.500.14352/45182
UL https://hdl.handle.net/20.500.14352/45182
LA eng
NO Ministerio de Ciencia e Innovación (MICINN)
NO Generalitat de Catalunya
NO Ministère de la Recherche et de l’Enseignement supérieur
NO Conseil Régional du Limousin
NO Fondation pour la Recherche Médicale (FRM)
NO Institut National de la Santé et de la Recherche Médicale (Inserm)
NO Centre National de la Recherche Scientifique (CNRS URA 2171)
NO Unión Europea
DS Docta Complutense
RD 6 abr 2025