Journal article

PcoE - A metal sponge expressed to the periplasm of copper resistance Escherichia coli. Implication of its function role in copper resistance

Matthias Zimmermann, Saumya R Udagedara, Chak Ming Sze, Timothy M Ryan, Geoffrey J Howlett, Zhiguang Xiao, Anthony G Wedd

Journal of Inorganic Biochemistry | ELSEVIER SCIENCE INC | Published : 2012

Abstract

Expression of the periplasmic protein PcoE of Escherichia coli is induced strongly by cupric salts under the control of the chromosomal copper tolerance system cusRS. Its isolation and study were complicated by de-amidation of Asn 54 and 103 at alkaline pH. Its apo form is essentially unstructured in solution and can be likened to a large unstructured multidentate ligand carrying multiple metal binding sites (15 Met; 10 His; 13 Asp, Glu; 10 Asn; 6 Lys). As expected, it binds multiple soft metal ions Cu(+) and Ag(+) non-cooperatively with the highest affinity for Cu(I) in the picomolar range (K(D)~10(-12) M). Binding of multiple soft ions induced dimerization and formation of some α-helical s..

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