The revised analyses of S.peucetius genome database available in our laboratory revealed twenty three cytochrome P450s (CYPs).seven ferredoxin reductases (FDRs) and six ferredoxins (FDXs).Even though numbers of FDXs and FDRs have been reported,sufficient details about the relevant homologous electron transport system in Streptomyces P450s is unclear.Since CYP166B1 was clustered with putative FDX6,we expressed and purified six FDR along with them and envisaged the primary pathway NADH→FDR4→FDX6→CYP166B1 for dealkylation of 7-ethoxycoumarin.