Catalyzes the radical-mediated synthesis of 7,8-didemethyl-8-hydroxy-5-deazariboflavin from 5-amino-5-(4-hydroxybenzyl)-6-(D-ribitylimino)-5,6-dihydrouracil. 5-amino-5-(4-hydroxybenzyl)-6-(D-ribitylimino)-5,6-dihydrouracil + S-adenosyl-L-methionine = 5'-deoxyadenosine + 7,8-didemethyl-8-hydroxy-5-deazariboflavin + H(+) + L-methionine + NH4(+) Binds 1 [4Fe-4S] cluster. The cluster is coordinated with 3 cysteines and an exchangeable S-adenosyl-L-methionine. Cofactor biosynthesis; coenzyme F0 biosynthesis. Consists of two subunits, CofG and CofH. Belongs to the radical SAM superfamily. CofG family. Truncated N-terminus.