Brucella abortus strain 2308 putative glucose and galactose transporter gene: cloning and characterization

The gene for the putative transporter for glucose and galactose from Brucella abortus strain 2308 was isolated by functional complementation of Escherichia coli strains lacking either glucose or galactose transport systems. The same two plasmid clones were isolated from each screen. These clones restored glucose and galactose transport to the respective E. coli strains. The sequence of the 1806 bp overlap between these two plasmids was determined. A 1242 bp ORF whose disruption eliminated complementation of both E. coli strains showed 36% identity with the E. coli fucP gene encoding a fucose transporter. These two transporters are members of the major facilitator superfamily, in which they represent a previously undescribed family. In addition, an incomplete gene similar to E. coli hisG was found. One of the plasmids complemented E. coli hisG mutants.