Ak2
Domain
Consists of three domains, a large central CORE domain and two small peripheral domains, NMPbind and LID, which undergo movements during catalysis. The LID domain closes over the site of phosphoryl transfer upon ATP binding. Assembling and dissambling the active center during each catalytic cycle provides an effective means to prevent ATP hydrolysis.
Function
Catalyzes the reversible transfer of the terminal phosphate group between ATP and AMP. Plays an important role in cellular energy homeostasis and in adenine nucleotide metabolism. Adenylate kinase activity is critical for regulation of the phosphate utilization and the AMP de novo biosynthesis pathways. Plays a key role in hematopoiesis.
Sequence Similarities
Belongs to the adenylate kinase family. AK2 subfamily.
Tissue Specificity
Present in the inner ear. Not detected in the vestibule at any developmental stage. Present at high level in the cochlea uniquely in the stria vascularis at postnatal day 7 but not at birth. Present within the lumen of the stria vascularis capillaries. Not detected in the capillaries or vessels of the adjacent connective tissue (at protein level).
Cellular localization
- Mitochondrion intermembrane space
Alternative names
AK 2, ATP-AMP transphosphorylase 2, ATP:AMP phosphotransferase, Adenylate monophosphate kinase, Ak2