1.5.7.3 N,N-dimethylglycine + 2 oxidized ferredoxin + H2O = sarcosine + formaldehyde + 2 reduced ferredoxin + 2 H+ (1) - 1.5.7.3 sarcosine + 2 oxidized ferredoxin + H2O = glycine + formaldehyde + 2 reduced ferredoxin + 2 H+ (2) -