Characterization of a Group of Anaerobically Induced, fnr -Dependent Genes of Salmonella typhimurium

Abstract

ABSTRACT We have previously reported the isolation of a group of anaerobically regulated, fnr -dependent lac fusions in Salmonella typhimurium and have grouped these oxd genes into classes based on map position. In order to identify these genes, we have replaced the original Mud- lac fusion in a member of each oxd class with the much smaller Mud- cam element, cloned the fusion, and determined DNA sequence sufficient to define the oxd gene. Several of the fusions correspond to previously known genes from S. typhimurium or Escherichia coli : oxd-4 = cbiA and oxd-11 = cbiK , oxd-5 = hybB , oxd-7 = dcuB , oxd-8 = moaB , oxd-12 = dmsA , and oxd-14 = napB ( aeg-46.5 ). Two other fusions correspond to previously unknown loci: oxd-2 encodes an acetate/propionate kinase, and oxd-6 encodes a putative ABC transporter present in S. typhimurium but not in E. coli .