exopolyphosphatase

Exopolyphosphatase is an enzyme that catalyzes the hydrolysis of the terminal phosphate group from linear polyphosphate molecules. Linear polyphosphates are chains of phosphate residues linked by phosphoanhydride bonds. Exopolyphosphatases typically release inorganic phosphate (Pi) as a product. These enzymes are found in a wide range of organisms, including bacteria, archaea, fungi, plants, and animals.

The activity of exopolyphosphatases is important for various cellular processes. They play a role in regulating intracellular polyphosphate levels, which are themselves involved in stress response, energy storage, and gene regulation. By breaking down polyphosphates, exopolyphosphatases can contribute to nutrient scavenging and the mobilization of stored energy. In some organisms, they are also implicated in the detoxification of excess phosphate.

Exopolyphosphatases are classified based on their substrate specificity and the type of polyphosphate chain they act upon. Some are specific for linear polyphosphates, while others may also act on cyclic polyphosphates. The active site of these enzymes typically contains metal ions, such as magnesium, which are essential for catalysis. The precise mechanisms of action and substrate binding vary among different exopolyphosphatases, reflecting their diverse evolutionary origins and functional roles. Understanding exopolyphosphatases is relevant to fields such as biochemistry, molecular biology, and biotechnology, where their enzymatic properties can be exploited for various applications.