Nucleotide sequence and features of the Bacillus licheniformis gnt operon

Bacillus licheniformis was able to utilize gluconate as the sole carbon source as efficiently as Bacillus subtilis did. Southern analysis indicated that B. licheniformis likely possesses only one gnt determinant. The nucleotide sequence (6278 bp) of the B. licheniformis DNA containing the gnt operon was determined, revealing the five complete open reading frames (ORF; genes). The putative product of the first gene, oug, did not show any significant homology to known proteins, but those of the second to fifth genes exhibited striking homology to the gntRKPZ genes of B. subtilis, respectively, indicating that they are the corresponding gnt genes of B. licheniformis. Not only is the organization of the gnt genes of these two Bacilli highly conserved, but so are the cis regulatory elements of their gnt operon. Sequence analysis of the upstream regions of these two gnt operons implied that a chromosome rearrangement in B. subtilis might have occurred immediately upstream of the gnt operon during evolution, causing it to diverge from a common ancestor into B. licheniformis and B. subtilis.