SilE is an intrinsically disordered periplasmic "molecular sponge" involved in bacterial silver resistance.

Ag(+) resistance was initially found on the Salmonella enetrica serovar Typhimurium multi-resistance plasmid pMG101 from burns patients in 1975. The putative model of Ag(+) resistance, encoded by the sil operon from pMG101, involves export of Ag(+) via an ATPase (SilP), an effluxer complex (SilCFBA) and a periplasmic chaperon of Ag(+) (SilE). SilE is predicted to be intrinsically disordered. We tested this hypothesis using structural and biophysical studies and show that SilE is an intrinsically disordered protein in its free apo-form but folds to a compact structure upon optimal binding to six Ag(+) ions in its holo-form. Sequence analyses and site-directed mutagenesis established the importance of histidine and methionine containing motifs for Ag(+) -binding, and identified a nucleation core that initiates Ag(+) -mediated folding of SilE. We conclude that SilE is a molecular sponge for absorbing metal ions. © The Authors. Molecular Microbiology Published by John Wiley & Sons Ltd.

Citation

Karishma R Asiani, Huw Williams, Louise Bird, Matthew Jenner, Mark S Searle, Jon L Hobman, David J Scott, Panos Soultanas. SilE is an intrinsically disordered periplasmic "molecular sponge" involved in bacterial silver resistance. Molecular microbiology. 2016 Sep;101(5):731-42

Mesh Tags

Substances

PMID: 27085056

search → result