The role of multi-copper oxidase CueO

The effect of a cueO mutation on global gene expression in E. coli has been analysed using whole genome oligonucleotide microarrays. A cueO mutant lacks a periplasmic multi-copper oxidase, an enzyme that is believed to be involved in the oxidation of cuprous and ferrous ions as well as phenolic compounds in the periplasm. Deletion renders the cell sensitive to copper and this toxicity is likely associated with increased oxidative stress in a cueO mutant. Keywords: genetic modification Triplicate cultures of E. coli MG1655 and the isogenic cueO mutant were grown to mid-exponential phase (OD600 0.8) in M9C supplemented with 2u­M FeSO4. RNA was extracted using Qiagen RNAprotect and RNeasy Mini Kit. Reference RNA was similarly purified from triplicate cultures of E. coli MG1655 grown on M9C supplemented with 2u­M FeCl3. RNA concentration and quality was assessed using an Aligent Bioanalyser 2100 NanoLabchip.