Figure 5. Comparison of the haem packing motifs of NrfB and NrfA (PDB code 1GU6) with NrfA₂H (PDB code 2J7A), HAO (PDB code 1FGJ) and STC (PDB code 1M1Q).

In the case of the putative NrfA–NrfB complex, the NrfB haems are shown in blue, the NrfA haems are shown in green and the numbers denote NrfA haems 2 and 5. Dimerization of NrfA occurs at the haem 5 interface (see Supplementary Figure S1 at http://www.BiochemJ.org/bj/406/bj4060019add.htm).