Title MINIREVIEW] Molecular architecture of the bacterial tripartite multidrug efflux pump focusing on the adaptor bridging model
Author Saemee Song1, Jin-Sik Kim1, Kangseok Lee2, and Nam-Chul Ha1*
Address 1Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Center for Food and Bioconvergence, Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 151-921, Republic of Korea, 2Department of Life Science, Chung-Ang University, Seoul 156-756, Republic of Korea
Bibliography Journal of Microbiology, 53(6),355-364, 2015,
DOI 10.1007/s12275-015-5248-4
Key Words multidrug resistance, Gram-negative bacteria, multidrug efflux pump, structure, TolC
Abstract Gram-negative bacteria expel a wide range of toxic substances through tripartite drug efflux pumps consisting of an inner membrane transporter, an outer membrane channel protein, and a periplasmic adaptor protein. These pumps form tripartite assemblies which can span the entire cell envelope, including the inner and outer membranes. There have been controversial findings regarding the assembly of the individual components in tripartite drug efflux pumps. Recent structural and functional studies have advanced our understanding of the assembly and working mechanisms of the pumps. Here, we re-evaluate the assembly models based on recent structural and functional studies. In particular, this study focuses on the ‘adaptor bridging model’, highlighting the intermeshing cogwheel-like interactions between the tip regions of the outer membrane channel protein and the periplasmic adaptor protein in the hexameric assembly.