Catalyzes the radical-mediated transfer of the hydroxybenzyl group from 4-hydroxyphenylpyruvate (HPP) to 5-amino- 6-ribitylamino-2,4(1H,3H)-pyrimidinedione to form 7,8-didemethyl- 8-hydroxy-5-deazariboflavin (FO) (By similarity). MQTIAAIAKLEEILTNNGISAQQALALLTTALPLATTSDPQEPLPPLLRALQTASDRLRQQQVGDTVTYVINRNINFTNICEQHCAFCAFRRDATASDAYWLNIETILSKVAEAVAQGATEICMQGGLNPAAKEGGSSLRYYQFLVREIKTAFPQIHLHAFSPQEIQFIAREDGCSYAQVIAALHEVGVDSMPGTAAEVLVDAVRSKICPEKIRTATWLEIVETAHRLGVWTTSTMLCGHIETPADQMAHLQHLQQLQQKALEHDYPARITEFILLPYVGELAPKAMRQWVGHHQPRLLPTLVLTAVARLFLGQWIVNHQPSWVKLGLRGATMALNWGCNDLGGTLMEEHITSVAGAQGGTGVSPEDLVAAIHSLGRTPQQRTTLYNPVGERQ 7,8-didemethyl-8-hydroxy-5-deazariboflavin synthase subunit 2 cofH 393 COFH_THEEB FO synthase subunit 2 tlr1597