Patent ID: 7799561

Claim:
A recombinant vector comprising a vector and a DNA sequence coding for a polypeptide, protein or protein fragment comprising the formula R 1 -Sp 1 -(His-Z 1 -His-Arg-His-Z 2 -His)-Sp 2 -R 2 , wherein (His-Z 1 -His-Arg-His-Z 2 -His) (SEQ ID NO: 24) is a metal ion-affinity peptide, R 1 is hydrogen, a polypeptide, protein or protein fragment, Sp 1 is a covalent bond or a spacer comprising at least one amino acid residue, R 2 is hydrogen, a polypeptide, protein or protein fragment, Sp 2 is a covalent bond or a spacer comprising at least one amino acid residue, Z 1 is an amino acid residue selected from the group consisting of Ala, Asn, Asp, Gln, Glu, Ile, Lys, Phe, Pro, Ser, Thr, Trp, and Val, and Z 2 is an amino acid residue selected from the group consisting of Ala, Asn, Asp, Cys, Gln, Glu, Gly, Ile, Leu, Lys, Met, Pro, Ser, Thr, Tyr, and Val, and wherein the recombinant vector is capable of directing expression of the DNA sequence in a compatible unicellular host organism.