Gessner, SophiaMartin, Zela Alexandria-MaeReiche, Michael A.Santos, Joana A.Dinkele, RyanRamudzuli, AtondahoDhar, Neerajde Wet, Timothy J.Anoosheh, SaberLang, Dirk M.Aaron, JesseChew, Teng-LeongHerrmann, JenniferMueller, RolfMcKinney, John DWoodgate, RogerMizrahi, ValerieVenclovas, CeslovasLamers, Meindert H.Warner, Digby F.2024-02-162024-02-162024-02-162023-08-0210.7554/eLife.75628https://infoscience.epfl.ch/handle/20.500.14299/203833WOS:001077770600001A DNA damage-inducible mutagenic gene cassette has been implicated in the emergence of drug resistance in Mycobacterium tuberculosis during anti-tuberculosis (TB) chemotherapy. However, the molecular composition and operation of the encoded 'mycobacterial mutasome' - minimally comprising DnaE2 polymerase and ImuA ' and ImuB accessory proteins - remain elusive. Following exposure of mycobacteria to DNA damaging agents, we observe that DnaE2 and ImuB co-localize with the DNA polymerase III beta subunit (beta clamp) in distinct intracellular foci. Notably, genetic inactivation of the mutasome in an imuB(AAAAGG) mutant containing a disrupted beta clamp-binding motif abolishes ImuB-beta clamp focus formation, a phenotype recapitulated pharmacologically by treating bacilli with griselimycin and in biochemical assays in which this beta clamp-binding antibiotic collapses pre-formed ImuB-beta clamp complexes. These observations establish the essentiality of the ImuB-beta clamp interaction for mutagenic DNA repair in mycobacteria, identifying the mutasome as target for adjunctive therapeutics designed to protect anti-TB drugs against emerging resistance.Life Sciences & BiomedicineMycobacterium TuberculosisMycobacterium SmegmatisInduced MutagenesisAntibiotic ResistanceAnti-EvolutionMutasomeOthertext::journal::journal article::research article