gene variant mutant 2-1 variant of MqsR a MqsR variant mutant that has two amino acid replacements at K3N and N31Y. Created through random mutagenesis by error prone PCR and confirmed by reduced cell growth in LB culture in shake flasks in of E. coli BW25113.This amino acid substitutions increase MqsR 2-1 stability without affecting its function, which results in increased toxicity relative to the wild type MqsR (part of the toxin antitoxin system MqsR/MqsA) colombos:mqsR_b3022.2-1_VARIANT PMID:22221537