Adenylate kinases (AKs) are nucleoside monophosphate kinases, which catalyse the phosphorylation of AMP by using ATP or GTP as phosphate donors. In humans, nine different AK isoenzymes have been identified (AK1-9). This entry represents AK3/4. Both AK3 and AK4 are localised in the mitochondrial matrix. AK3 is expressed in liver, heart and skeletal muscle, while AK4 is expressed predominantly in kidney []. Despite its homology with AK3, AK4 shows no enzymatic activity in vitro []. AK4 contains an unusual feature of an N-terminal mitochondrial import sequence that remains uncleaved after import into the mitochondria []. This entry also includes yeast mitochondrial adenylate kinase, Adk2. Its 3' sequence varies with strain background [].
Adenylate kinases (AKs) are nucleoside monophosphate kinases, which catalyse the phosphorylation of AMP by using ATP or GTP as phosphate donors. In humans, nine different AK isoenzymes have been identified (AK1-9) []. This entry represents AK4 (also known as adenylate kinase 3-like). Despite its homology with other AKs, AK4 shows no enzymatic activity in vitro []. AK4 is expressed predominantly in kidney and weakly in liver, heart and brain []. It is localised in the mitochondrial matrix []. It contains an unusual feature of an N-terminal mitochondrial import sequence that remains uncleaved after import into the mitochondria [].
