This model represents an enzyme, O-succinylbenzoate-CoA ligase, which is involved in the fourth step of the menaquinone biosynthesis pathway. O-succinylbenzoate-CoA ligase, together with menB - naphtoate synthase, take 2-succinylbenzoate and convert it into 1,4-di-hydroxy-2- naphtoate. [Biosynthesis of cofactors, prosthetic groups, and carriers, Menaquinone and ubiquinone]