New method tracks metal-ion movement in periplasmic proteins
Monday, November 3, 2014 - 09:01
in Biology & Nature
Copper is an essential nutrient for most organisms. However, it is toxic at high concentrations and, in fact, is used by macrophages to kill invading microbes. To counter the lethal effects of both environmental and host-defense onslaught, bacteria have devolved intricate efflux systems that impart full copper resistance. The periplasmic CusCBA pump in Escherichia coli is one example of this type of efflux system (Figure 1). The Cus system is structurally similar to the bacterial RND-type (resistance nodulation division) drug efflux complexes with some striking differences in (1) the involvement of its periplasmic adapter protein CusB, which binds Cu+ and Ag+, and (2) the co-expression of the Cu+/Ag+ metallochaperone CusF.