The iron-responsive regulator Fur of Campylobacter jejuni is expressed from two separate promoters

A lacZ-based reporter gene system was used to identify the promoter of the Campylobacter jejuni iron-responsive gene regulator Fur. In other Gram-nega tive bacteria, the fur promoter is usually located directly upstream of the fur gene and is often autoregulated in response to iron. In this study we demonstrate that expression of the C. jejuni fur gene is controlled from tw o promoters located in front of the first and second open reading frames up stream of fur. Neither of these promoters was iron-regulated, and the prese nce of both promoters in front of fur gives higher expression of the lacZ r eporter than with either promoter alone. Expression from two distal promote rs might be a mechanism for regulating the level of the C. jejuni Fur prote in in response to unknown stimuli. (C) 2000 Published by Elsevier Science B .V. on behalf of the Federation of European Microbiological Societies.