exopolyphosphatase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: polyphosphate(n) + H2O = polyphosphate(n-1) + phosphate. [EC:3.6.1.11]

Exopolyphosphatase activity refers to the enzymatic hydrolysis of inorganic polyphosphate chains, which are linear polymers of orthophosphate residues linked by phosphoanhydride bonds. This process removes phosphate groups from the end of the polyphosphate chain, resulting in the formation of shorter polyphosphate molecules or orthophosphate. Exopolyphosphatases are ubiquitous enzymes found in all living organisms, from bacteria to humans. They play diverse roles in cellular metabolism, including:

* **Energy metabolism:** Exopolyphosphatases can release inorganic phosphate, which is essential for ATP synthesis and other metabolic processes.
* **Signal transduction:** Polyphosphates can act as signaling molecules, and exopolyphosphatases can regulate their levels by hydrolyzing them.
* **Stress response:** Exopolyphosphatases are involved in the cellular response to stress conditions such as starvation, oxidative stress, and heat shock.
* **Phosphorylation:** Exopolyphosphatases can contribute to the phosphorylation of proteins and other molecules, influencing their function.
* **DNA replication and repair:** Polyphosphates are involved in DNA replication and repair, and exopolyphosphatases can regulate their availability.
* **Bacterial virulence:** In bacteria, exopolyphosphatases can contribute to virulence by promoting biofilm formation and resistance to antibiotics.

The specific molecular function of exopolyphosphatase activity varies depending on the enzyme and its cellular context. However, the common thread is the hydrolysis of polyphosphate chains, which liberates inorganic phosphate and regulates the levels of polyphosphate signaling molecules. This process is crucial for maintaining cellular homeostasis and responding to environmental challenges.'
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Proteins (1)

Compounds (1)