The iron coordination structure of nitric oxide reductase (NOR) was in
vestigated by iron K-edge EXAFS. The EXAFS of the ferrous form of NOR
is similar to that of cytochrome P450cam (P450cam), but the EXAFS of i
ts ferrous-CO forms exhibited a subtle but significant difference from
those of P450cam. The structural basis of unique function of the NOR
is discussed.