Enzymic formation of the type-III prophyrin macrocycle from unrearranged AP·AP pyrromethane
Abstract
The unrearranged [14C]-AP·AP pyrromethane (2) is converted by deaminase–cosynthetase into uro'gen-III (7), thus supporting initial head-to-tail combination of porphobilinogen units for biosynthesis of the natural type-III porphyrins.