Figure 1: Genome structure and sequence analysis of mycobacterial SDRs.

A number of SDRs containing an insertion at the NAD binding site appear in mycobacterial organisms. These SDRs always appear in conjunction with a number of genes that appear to be involved in the biosynthesis of the proposed redox partner mycofactocin. Multiple sequence alignment of the ten crystal structures determined here in comparison with 10 other oxidoreductases of known structure which lack the insertion in the primary sequence. The PDB code for each structure is listed. The structures described here all contain NAD (sequences 1–9) except for 3OEC (sequence 10), whereas for the structures described elsewhere 5 representative examples of NADP (sequences 11–15) or NAD (sequences 16–20) bound structures were selected and the ligand identity is also listed. The magenta cylinders indicate α helices, whereas the blue arrows indicate β strands. The insertion loop is shown as a gray arrow and labeled, and the loop region that is often disordered is also shown as a gray arrow and labeled.