biostudies-literatureNasher FUKRI | Biotechnology and Biological Sciences Research CouncilNERC Environmental Bioinformatics CentreNatural Environment Research CouncilBiotechnology and Biological Sciences Research Councile0042121https://www.ebi.ac.uk/biostudies/studies/S-EPMC8765430biostudies-literatureUnknown204(1)The paralogues RrpA and RrpB, which are members of the MarR family of DNA binding proteins, are important for the survival of the global bacterial foodborne pathogen Campylobacter jejuni under redox stress. We report that RrpA is a positive regulator of <i>mdaB</i>, encoding a flavin-dependent quinone reductase that contributes to the protection from redox stress mediated by structurally diverse quinones, while RrpB negatively regulates the expression of <i>cj1555c</i> (renamed <i>nfrA</i> for NADPH-flavin reductase A), encoding a flavin reductase. NfrA reduces riboflavin at a greater rate than its derivatives, suggesting that exogenous free flavins are the natural substrate. MdaB and NfrA both prefer NADPH as an electron donor. Cysteine substitution and posttranslational modification analJournal of bacteriologyMdaB and NfrA, Two Novel Reductases Important in the Survival and Persistence of the Major Enteropathogen Campylobacter jejuni.PMC8765430NE/L011956/1BB/S011269/1BB/R012504/1BBS/E/F/000PR10349BB/S014497/1Lynham SNasher FKelly DJGundogdu OElmi ALehri BBaker DSingh DGoram RTaylor AJStabler RWren BWIjaz UZfalseMdaB and NfrA, Two Novel Reductases Important in the Survival and Persistence of the Major Enteropathogen Campylobacter jejuni.The paralogues RrpA and RrpB, which are members of the MarR family of DNA binding proteins, are important for the survival of the global bacterial foodborne pathogen Campylobacter jejuni under redox stress. We report that RrpA is a positive regulator of <i>mdaB</i>, encoding a flavin-dependent quinone reductase that contributes to the protection from redox stress mediated by structurally diverse quinones, while RrpB negatively regulates the expression of <i>cj1555c</i> (renamed <i>nfrA</i> for NADPH-flavin reductase A), encoding a flavin reductase. NfrA reduces riboflavin at a greater rate than its derivatives, suggesting that exogenous free flavins are the natural substrate. MdaB and NfrA both prefer NADPH as an electron donor. Cysteine substitution and posttranslational modification anal2022-01-01T00:00:00Z2022 Jan2026-06-07T03:20:08.892Z2025-04-05T19:59:39.014ZS-EPMC87654303460637310.1128/JB.00421-21