Involved in the biosynthesis of phylloquinone (vitamin K1). Converts o-succinylbenzoyl-CoA (OSB-CoA) to 1,4-dihydroxy-2-naphthoyl-CoA (DHNA-CoA) (By similarity). 2-succinylbenzoyl-CoA + H(+) = 1,4-dihydroxy-2-naphthoyl-CoA + H2O The hydrogencarbonate anion plays the same catalytic role (proton acceptor) as the side-chain carboxylate group of the essential 'Asp-185' found in actinobacteria, archaea, bacteroidetes, and deltaproteobacteria. Homohexamer. Belongs to the enoyl-CoA hydratase/isomerase family. MenB subfamily.