Amino acid sequence alignment for the binding region flanking the re-face of the FMN cofactor for six members of the diflavin reductase family including flavocytochrome P450BM-3, human cytochrome P450 reductase (CPR), rat neuronal nitric oxide synthase (nNOS), E. coli sulfite reductase (SR), human methionine synthase reductase (MSR), and human novel reductase 1 (NR1). The conserved glycine residue highlighted in red is absent in BM3. The conserved glycine and tandem proline residues are highlighted in blue.