Construction and properties of a triprotein containing the high-affinity nickel transporter of Alcaligenes eutrophus.

The high-affinity nickel transporter of Alcaligenes eutrophus H16 is encoded by gene hoxN, which maps within the hydrogenase gene cluster of megaplasmid pHG1. A tripartite gene fusion was constructed, consisting of (i) the Escherichia coli lacZ gene for beta-galactosidase, (ii) a segment encoding an endoproteolytically cleavable peptide, and (iii) the A. eutrophus gene hoxN. An E. coli strain harboring this construct (plasmid pCH307) efficiently produced the corresponding triprotein upon induction. A broad-host-range derivative of pCH307 was shown to complement an A. eutrophus HoxN- mutant.