1H, 13C, 15N backbone NMR assignments of the Staphylococcus aureus small multidrug-resistance pump (Smr) in a functionally active conformation.

ABSTRACT

The plasmid-encoded small multidrug resistance pump from S. aureus transports a variety of quaternary ammonium and other hydrophobic compounds, enhancing the bacterial host's resistance to common hospital disinfectants. The protein folds as a homo-dimer of four transmembrane helices each, and appears to be fully functional only in lipid bilayers. Here we report the backbone resonance assignments and implied secondary structure for (2)H(13)C(15)N Smr reconstituted into lipid bicelles. Significant changes were observed between the chemical shifts of the protein in lipid bicelles compared to those in detergent micelles.