Schematic structure of BbbqrA and phylogenetic tree. Diagram of BbbqrA; the ORF is represented by an arrow. Vertical lines (gray) within the ORF and numbers identify the two introns and intron lengths, respectively. Genetic elements identified (5′- and 3′- upstream and downstream sequences, respectively) are represented as follows: yellow square, TATA box (−57 bp); empty square CCAAT box (−600), inverted red triangle, inverted GC box (−308); blue circles (XRE) (−235, −267, −326, −539, −599, −606, −616, −1,079, and −1,181); pale orange circle (STRE) (−288); light green triangle: potential transcription termination.