Involved in the non-oxidative decarboxylation and detoxification of phenolic derivatives under both aerobic and anaerobic conditions (PubMed:18388975). Flavin prenyltransferase that catalyzes the synthesis of the prenylated FMN cofactor (prenyl-FMN) for phenolic acid decarboxylase (By similarity). dimethylallyl phosphate + FMNH2 = phosphate + prenyl-FMNH2 Homododecamer. Up-regulated by salicylate via the transcriptional regulator BsdA. A triple bsdB-bsdC-bsdD deletion mutant no longer converts vanillin to guaiacol, the conversion stops at vanillic acid (PubMed:26658822). It is not known, if phenolic acid decarboxylase forms a complex composed of BsdB, BsdC and BsdD. The term subunit is often used in reference to the operon, however there is no experimental evidence to prove the existence of the complex. Belongs to the UbiX/PAD1 family. YclB subfamily.