NreB from Achromobacter xylosoxidans 31A Is a Nickel-Induced Transporter Conferring Nickel Resistance

Abstract
There are two distinct nickel resistance loci on plasmid pTOM9 fromAchromobacter xylosoxidans 31A, ncc andnre. Expression of the nreB gene was specifically induced by nickel and conferred nickel resistance on bothA. xylosoxidans 31A and Escherichia coli. E. coli cells expressing nreB showed reduced accumulation of Ni2+, suggesting that NreB mediated nickel efflux. The histidine-rich C-terminal region of NreB was not essential but contributed to maximal Ni2+ resistance.