Flavodoxin Is Required for the Activation of the Anaerobic Ribonucleotide Reductase

The inactive anaerobic ribonucleotide reductase from Escherichia coli is transformed by a multienzyme system and S-adenosylmethionine + NADPH into a radical protein that is enzymatically active. One of the activating enzyme components was earlier shown to be ferredoxin (flavodoxin):NADP+ reductase. Here we present evidence that flavodoxin, but not ferredoxin, also is a component of the system. Light reduced deazaflavin can substitute for the flavodoxin system. An additional unidentified low-molecular weight component further stimulates the reaction.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30392/3/0000010.pd