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
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..View full abstract
Awarded by Australian Research Council
We thank the Australian Research Council for financial support under grant A29930204. We also thank Drs James Hickey and Paul Donnelly of the University of Melbourne for providing the Cu<SUP>I</SUP> probe CS1 used in this work.