title: Identification of Escherichia coli ygaQ and rpmG as novel mitomycin C resistance factors implicated in DNA repair.
abstract: Using the ASKA (A Complete Set of Escherichia coli K-12 ORF Archive) library for genome-wide screening of E. coli proteins we identified that expression of ygaQ and rpmG promotes mitomycin C resistance (MMC(R)). YgaQ mediated MMC(R) was independent of homologous recombination involving RecA or RuvABC, but required UvrD. YgaQ is an uncharacterized protein homologous with α-amylases that we identified to have nuclease activity directed to ssDNA of 5' flaps. Nuclease activity was inactivated by mutation of two amino acid motifs, which also abolished MMC(R). RpmG is frequently annotated as a bacterial ribosomal protein, although forms an operon with MutM glycosylase and a putative deubiquitinating (DUB) enzyme, YicR. RpmG associated MMC(R) was dependent on MutM. MMC(R) from RpmG resembles DNA repair phenotypes reported for 'idiosyncratic ribosomal proteins' in eukaryotes.
authors.affiliation: School of Life Sciences, The University of Nottingham, Nottingham NG72UH, U.K. ed.bolt@nottingham.ac.uk.
authors.forename: Edward L
authors.initials: EL
authors.lastname: Bolt
authors.affiliation: School of Life Sciences, The University of Nottingham, Nottingham NG72UH, U.K.
authors.forename: Tabitha
authors.initials: T
authors.lastname: Jenkins
authors.affiliation: School of Life Sciences, The University of Nottingham, Nottingham NG72UH, U.K.
authors.forename: Valeria Moreira
authors.initials: VM
authors.lastname: Russo
authors.affiliation: School of Life Sciences, The University of Nottingham, Nottingham NG72UH, U.K.
authors.forename: Sharlene
authors.initials: S
authors.lastname: Ahmed
authors.affiliation: School of Life Sciences, The University of Nottingham, Nottingham NG72UH, U.K.
authors.forename: James
authors.initials: J
authors.lastname: Cavey
authors.affiliation: School of Life Sciences, The University of Nottingham, Nottingham NG72UH, U.K.
authors.forename: Simon D
authors.initials: SD
authors.lastname: Cass
mesh_terms: D024881:Drug Resistance, Bacterial / Q000187:drug effects* / Q000502:physiology; D048168:Escherichia coli K12 / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000096:biosynthesis* / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects* / Q000235:genetics; D016685:Mitomycin / Q000494:pharmacology*; D012269:Ribosomal Proteins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins; D012269:Ribosomal Proteins; C489052:rpmG protein, E coli; D016685:Mitomycin
keywords: DNA repair; homologous recombination; mitomycin C; rpmG; ygaQ