Bacterial membrane drug efflux and receptor proteins

Abstract

Multidrug (Mdr) efflux proteins (1) are widespread amongst microorganisms, including pathogens. These membrane proteins contribute to emerging antibiotic resistance. Two-component system (TCS) receptor membrane proteins (2) play key roles in metabolism and sensitivity to antibiotics of many microorganisms. The design of novel antibacterial drugs would be greatly facilitated by knowledge of the structures of these membrane proteins, which are poorly understood because of the difficulties of obtaining purified protein and crystals of quality. We describe a structural genomics strategy for the amplified expression, purification and characterisation of such proteins.

Over thirty Mdr and TCS membrane proteins have been purified from Bacillus cereus, Bacillus subtilis, Brucella melitensis, Campylobacter jejuni, Escherichia coli, Enterococcus faecalis, Helicobacter pylori, Neisseria meningitidis, Staphylococcus aureus, and Streptomyces coelicolor. Proteins from B. cereus, E. faecalis, H. pylori and S. aureus will be used as detailed examples to illustrate the strategy.

The success of this strategy is an important step towards reproducible production of transport and receptor proteins for the screening of drug binding and for optimisation of crystallisation conditions to enable subsequent structure determination and drug design.