Ecies (32). Such enzymes could provide another means for Chl d biosynthesis. A. marina codes for 12 proteins with putative radical SAM motifs, far more than expected from an oxygen-producing cyanobacterium. Of these 12, two (AM1 5023 and AM1 5798) share very little homology with other sequenced cyanobacteria. The Chl d biosynthesis pathway may not be as simple as expected. Unlike the formyl side c