Bioinformatics Study of m.9053G>A Mutation at the ATP6 Gene in Relation to Type 2 Diabetes Mellitus and Cataract Diseases

The mitochondrial disease often associated with various illnesses in relation to the activity of cells metabolites and the synthesis of adenosine triphosphate (ATP), including alteration in the mitochondrial DNA. The mutation of m.9053G>A at the ATP6 gene was found in patients with type 2 diabetes mellitus (DM type 2) and cataract. Therefore, this mutation is predicted to be clinical features of the 2 diseases. ATP6 gene encodes protein subunit of ATPase6, a part of ATP synthase, which is important in the electron transfer and proton translocation in intracellular respiration system. This study aims to investigate the mutation effect of m.9053G>A at the ATP6 gene (S167N) to the structure and function of ATPase6 using bioinformatics method. The structure of ATPase6 was constructed using homology modeling method. The crystal structure of bovine's ATP synthase (Protein Data Bank ID 5FIL) was used as a template because of high sequence similarity (77%) and coverage (96%) of the input sequence. The effect of mutation was investigated at the proton translocation channel of ATPase6. It is predicted that the channel was disrupted due to changes in electrostatic potential from serine to asparagine. Furthermore, molecular docking suggests that water binding on the proton translocation channel in the S167N mutant was different from the wild type. The result of this study is hoped to be useful in the development of a new genetic marker for DM type 2 and cataract.