Adenylate Kinase 4 (AK4)

AK4 encodes a member of the adenylate kinase family of enzymes. The encoded protein is localized to the mitochondrial matrix. Adenylate kinases regulate the adenine and guanine nucleotide compositions within a cell by catalyzing the reversible transfer of phosphate group among these nucleotides. Five isozymes of adenylate kinase have been identified in vertebrates. Expression of these isozymes is tissue-specific and developmentally regulated. A pseudogene for this gene has been located on chromosome 17. Three transcript variants encoding the same protein have been identified for this gene. The deduced 223-amino acid protein shares 58% amino acid identity with bovine Ak3. Both proteins have an N terminus capable of forming an amphipathic alpha helix necessary for translocation into mitochondria.