CKMT2 (creatine kinase, mitochondrial 2 (sarcomeric)) is a creatine kinase isoenzyme, (reversibly) catalyzing the production of ATP from ADP by converting Phosphocreatine to creatine. Phosphocreatine serves as an energy reservoir for the rapid generation of ATP.Mitochondrial creatine kinase exists as two isoenzymes, sarcomeric mitochondrial creatine kinase (CKMT2) and ubiquitous creatine kinase; these are encoded by separate genes. Mitochondrial creatine kinases occurs in two different oligomeric forms: dimers and octamers, in contrast to the exclusively dimeric cytosolic creatine kinase isoenzymes. Sarcomeric mitochondrial creatine kinase has 80% homology with the coding exons of ubiquitous mitochondrial creatine kinase. The CKMT2 gene contains sequences homologous to several motifs that are shared among some nuclear genes encoding mitochondrial proteins and thus may be essential for the coordinated activation of these genes during mitochondrial biogenesis. Three transcript variants encoding the same protein have been found for this gene.