Figure 6. Potential roles of PTMs on MDH.

At the center, the three-dimensional structure of the porcine cytoplasmic MDH dimer is represented (PDB: 5mdh). The active site is highlighted in yellow, the dimer interface in magenta, and the citrate synthase surface for the metabolon complex in cyan. The NAD⁺ ligand is shown in yellow spheres. Properties that can be modulated by PTMs, including defining the directionality of the reaction, altering enzymatic characteristics (e.g. K_m and V_max), defining the subcellular localization, regulating the stability of the quaternary structure and protein–protein interactions protrude around the circle. This figure was generated using PyMOL and BioRender.com.