Enterocin Cross-Resistance Mediated by ABC Transport Systems Teso Pérez, Claudia Martínez Bueno, Manuel Peralta Sánchez, Juan Manuel Valdivia Martínez, Dolores Eva Maqueda Abreu, Mercedes Farez Vidal, María Esther Martín Platero, Antonio Manuel Enterocin ABC transporter Bacteriocin immunity MR10A/B AS-48 In their struggle for life, bacteria frequently produce antagonistic substances against competitors. Antimicrobial peptides produced by bacteria (known as bacteriocins) are active against other bacteria, but harmless to their producer due to an associated immunity gene that prevents selfinhibition. However, knowledge of cross-resistance between different types of bacteriocin producer remains very limited. The immune function of certain bacteriocins produced by the Enterococcus genus (known as enterocins) is mediated by an ABC transporter. This is the case for enterocin AS-48, a gene cluster that includes two ABC transporter-like systems (Transporter-1 and 2) and an immunity protein. Transporter-2 in this cluster shows a high similarity to the ABC transporter-like system in MR10A and MR10B enterocin gene clusters. The aim of our study was to determine the possible role of this ABC transporter in cross-resistance between these two different types of enterocin. To this end, we designed different mutants (Tn5 derivative and deletion mutants) of the as-48 gene cluster in Enterococcus faecalis and cloned them into the pAM401 shuttle vector. Antimicrobial activity assays showed that enterocin AS-48 Transporter-2 is responsible for cross-resistance between AS-48 and MR10A/B enterocin producers and allowed identification of the MR10A/B immunity gene system. These findings open the way to the investigation of resistance beyond homologous bacteriocins. 2021-07-06T10:32:48Z 2021-07-06T10:32:48Z 2021 info:eu-repo/semantics/article Teso-Pérez, C.; Martínez-Bueno, M.; Peralta-Sánchez, J.M.; Valdivia, E.; Maqueda, M.; Fárez-Vidal, M.E.; Martín-Platero, A.M. Enterocin Cross-Resistance Mediated by ABC Transport Systems. Microorganisms 2021, 9, 1411. https://doi.org/10.3390/ microorganisms9071411 http://hdl.handle.net/10481/69547 10.3390/microorganisms9071411 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España MDPI