Biophysical Characterization and Structural Studies of Small Multidrug Resistance Family of Transporters

Abstract

The Small Multidrug Resistance (SMR) family of membrane proteins is known for conferring resistance to a wide range of antibiotics and xenobiotic compounds in bacteria. Moreover, their small size and rare dual topology architecture have made them a suitable model system for studying membrane protein mechanism and evolution. Despite many years of research on multidrug exporters in the SMR family, the family's main function has remained a mystery. We show for the first time, using phylogenetic studies and membrane transport assays, that the majority members of this family are not drug exporters.