Turner, RaymondBeketskaia, Maria2014-09-022014-11-172014-09-022014Beketskaia, M. (2014). Phenotypic Association between the Outer Membrane Protein OmpW and the Small Multi-Drug Resistance Protein EmrE in Escherichia coli (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/27333http://hdl.handle.net/11023/1712In Escherichia coli, the small multidrug resistance (SMR) transporter protein EmrE confers host resistance to a broad range of toxic quaternary cationic compounds (QCCs) via proton motive force in the cytoplasmic membrane. Biologically produced QCCs also act as EmrE osmoprotectant substrates within the cell and participate in host pH regulation and osmotic tolerance. Although E. coli EmrE is one of the most well-characterized SMR members, it is unclear how the substrates that it transports into the periplasmic space escape across the outer membrane (OM) in Gram-negative bacteria. We tested the hypothesis that E. coli EmrE relies on an unidentified OM protein (OMP) to complete the extracellular release of its QCC. By conducting pH-based phenotypic growth screens, complementation and methyl viologen (MV) resistance assays, we have confirmed that EmrE relies on the presence of an OMP, specifically OmpW, to complete its extracellular substrate efflux across the OM.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.MicrobiologyEmrEOmpWSMRMembraneproteinResistanceporinmaster thesis10.11575/PRISM/27333