Chemistry Commons^™

Acrb Multidrug Efflux Pump Of Escherichia Coli: Composite Substrate-Binding Cavity Of Exceptional Flexibility Generates Its Extremely Wide Substrate Specificity, Edward Yu, Julio R. Aires, Hiroshi Nikaido

Edward Yu

Gram-negative bacteria have, in general, much higher intrinsic levels of resistance to various antibiotics, antiseptics, dyes, and detergents than do gram-positive bacteria. This is, in part, due to the effectiveness of the outer membrane as a barrier. The porin channels exclude large compounds (for example, vancomycin) and drastically slow down the influx of most antibiotics, which are usually much larger than common nutrients. Most antibiotics and chemotherapeutic agents that act on targets in the cytosol must cross the inner, cytoplasmic membrane, usually by spontaneous diffusion, and this necessitates their being at least moderately lipophilic. These compounds can in principle diffuse …