... including the catalytic tyrosine and lysine resi-dues involved in the acid–base mechanism, the divalentcation-binding residues, and two Rossman domains(GXGXXG) implicated in cofactor binding ... citrate) into pyruvate in the presence of divalent metals and in the absence of nicotinamide cofactors [7]. Noteworthy, the activity of MEF proteins contribute to the intracellular pHhomeostasis since ... con-served nucleotide binding residues in the active site(Fig. 1B) are presumably involved in the ATP, ADP,NAD and NADH inhibition pattern of CitM and MaeE. However, binding of such compounds to...