We are studying an unknown regulator of E. coli, YeiL. It carries Fe-S cluster characteristics of proteins involved in adaptation to changing redox environment. Our transcriptomic studies have drawn a link between YeiL and anaerobic respiration of nitrate. Beyond this aspect, a lot of metabolism stress adaptation genes are regulated. We are now wondering which genes are directly regulated by YeiL to precisely define its biological role. This regulator is conserved in enterobacteria including pathogens. As anaerobic respiration in an important adaptation metabolism during gut colonization, we think that the understudied YeiL regulator could have a role for bacterial pathogenesis.
To decipher the YeiL direct regulon, we propose to use the ChIP-Seq technology. We have fused either the yeiL wild type allele or the yeiL* mutated allele, that is unable to bind the metallic center (apo-form of the regulator), to an HA-tag. We have checked that these proteins fusions were still active to regulate gene expression. Gene enrichment will be studied by comparing hits in a strain that contain the empty vector (pTet-HA), the fusion with the wild type yeiL gene, or a fusion with the modified yeiL* gene encoding the apo-form of the regulator.