Structural and dynamical insights into SilE silver binding from combined analytical probes

Abstract

Silver has been used for its antimicrobial properties to fight infection for thousands of years. Unfortunately, some Gram-negative bacteria have developed silver resistance causing the death of patients in a...

The battle for silver binding: How the interplay between the SilE, SilF, and SilB proteins contributes to the silver efflux pump mechanism

“…Furthermore, one may still wonder whether SilE only induces silver sequestration or may directly bind to SilB via SilF. This question arises from the fact that SilE can bind six silver ions ( 7 ) similarly to the SilB hexamer structure that may bind up to six SilF. The results of our experiments demonstrate that SilE does not bind to neither SilF nor SilB and that its binding affinity for silver is weaker compared to the affinity of silver for SilF and SilB.…”

“…It is thus an ongoing challenge to disentangle the functional mechanism of action that governs silver resistance and the corresponding interplay between SilCBA, SilF, and SilE of S. typhimurium . At present, only a few proteins of the sil system have been characterized, including SilE of S. typhimurium ( 7 ) and SilB from Cupriavidus metallidurans CH34, for which the structure and dynamics of its N- and C-terminus region, with and without silver, have been investigated ( 8 , 9 ). While the C terminus folds into a SilF-like domain and binds silver ions ( 8 ), its N-terminus region is structured in solution and binds a silver ion that is caught between three conserved methionines ( 9 ).…”