Mitochondria are dynamic organelles that constantly undergo morphological changes. These changes are controlled by two opposing processes, which are mitochondrial fission and fusion. Mitochondrial fission is mediated by cytosolic dynamin-related protein 1 (Drp1) that can polymerizes at the mitochondrial membrane and constrict the organelle. Recently, two mitochondrial dynamic proteins named MiD49 and MiD51 have been identified to be the receptors important for Drp1 recruitments to the mitochondrial membrane. Previously, we have managed to solve the structure of MiD51. From the structure, we found that MiD51 adopts nucleotidyltransferase protein fold. Interestingly, we have identified a loop in the nucleotidyltransferase domain that is important for the recruitment of Drp1 to the mitochondrial membrane. Thus, our current goal is to use structural techniques such as X-ray crystallography and Small Angle X-ray Scattering (SAXS) to elucidate the structure of MiD49 as well as the structures of MiD49 or MiD51 in complex with Drp1 to further understand the molecular basis of Drp1 recruitment to the mitochondrial membrane.