FIG. 1.

Structure of AdoCbl, aka coenzyme B₁₂. The indicated gene functions involved in the synthesis of different parts of AdoCbl are those found in serovar Typhimurium. AdoCba's differ in their structures by the nature of the lower-ligand base (reviewed in reference 44). (A) Cbi, synthesized by CbiABCDETFGHJKLMNQOP. (B) Cobyric acid, synthesized by CbiACDETFGHJKLMNQOP. (C) 1-Aminopropanol-O-2-phosphate, synthesized by CobD. (D) Nucleotide loop, assembled by CobUTSC. Me, methyl; FMN, flavin mononucleotide.