Characterisation of a new operon encoding a Zur-like protein and an associated ABC zinc permease in Listeria monocytogenes

Metal ions uptake is mainly studied for iron, as it has often been implicated in bacterial virulence. Although Listeria,monocytogenes virulence is expected to be controlled by the iron availability, little is known about such an uptake and its regulation. We describe the analysis of the first operon involved in metal ions uptake in L. monocytogenes. Its three ORFs encode respectively (1) an ABC protein, likely implicated in zinc uptake, (2) a hydrophobic membrane protein, generally associated with ABC proteins and (3) a ferric uptake regulator-like protein, that we named zinc uptake regulator, as it shows strong homologies with the zinc uptake regulator, a regulator of the zinc homeostasis in Bacillus subtilis. The expression of this operon is regulated by the zinc concentration. (C) 1999 Published by Elsevier Science B.V. All rights reserved.