Turner, RaymondSaleh, Marwah2014-08-212015-08-222014-08-212014http://hdl.handle.net/11023/1691The study of the molecular mechanism of substrate recognition/binding by multidrug resistance transporters has taken different approaches. I have utilized a PCR-driven site-directed mutagenesis analysis to alter conserved amino acid residues within the Escherichia coli small multidrug transporter, EmrE. The EmrE variants generated were further assessed for their resistance ability to 19 structurally different quaternary cationic compounds (QCC) using a high-throughput microtitre plate assay. The underlying hypothesis is that the mutation of conserved amino acids will alter the resistance profile of EmrE to structurally different QCC and identify the specificity of these residues to specific characteristic(s) of QCC. Based on 1,254 resistance profiles, the plasticity of EmrE binding pocket can be explained by the presence of conserved amino acid residues with different substrate preferences. The significance of studying EmrE is that it provides an excellent model for understanding the polysubstrate specificity on a molecular basis relatable to other major transporters.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.GeneticsMicrobiologyBiochemistryMultidrug ResistanceMultidrug transporterSmall Multidrug Resistance ProteinsEmrESite directed mutagenesismaster thesis10.11575/PRISM/28135