Characterization of Metal Binding Protein ZP and its His-rich Peptides from a Halophilic Marine Bacterium Chromohalobacter salexigens

Abstract

We cloned a gene, Csal-0188, from genomic DNA of Chromohalobacter salexigens DSM 3043^T. This gene was annotated to encode Zn-binding protein（ZP）, which showed high homology with the His-rich metal binding protein（HP）we reported. His-tag-ZP was successfully expressed in Escherichia coli and purified. ZP was constructed with a thrombin digestion site so that His-tag could be removed. ZP and chemically synthesized oligo-peptides from the His-rich insertion sequence of ZP showed several metal binding activities. This His-rich peptide was found to bind to Ni column in the presence of 8 M urea, showing clear binding under denaturation conditions, like conventional His-tag.