ribonuclease A activity

Definition

Target type: molecularfunction

Catalysis of the endonucleolytic cleavage of RNA to 3'-phosphomononucleotides and 3'-phosphooligonucleotides ending in C-P or U-P with 2',3'-cyclic phosphate intermediates. [EC:4.6.1.18]

Ribonuclease A activity is a catalytic activity that cleaves RNA molecules. It is typically performed by enzymes known as ribonucleases, which specifically target phosphodiester bonds within the RNA backbone. The mechanism of ribonuclease A activity involves the following steps: 1. **Binding of RNA to the enzyme:** Ribonuclease A binds to the RNA substrate through interactions between its active site and the sugar-phosphate backbone and bases of the RNA molecule. 2. **Hydrolysis of the phosphodiester bond:** The enzyme utilizes two histidine residues in its active site to catalyze the hydrolysis of the phosphodiester bond. One histidine acts as a general base to deprotonate a water molecule, making it a better nucleophile. The other histidine acts as a general acid to protonate the leaving group, facilitating the cleavage reaction. 3. **Release of the cleaved products:** Once the phosphodiester bond is broken, the two RNA fragments are released from the enzyme. The products of the reaction are typically a 5'-hydroxyl group and a 3'-phosphate group. Ribonuclease A activity is essential for various cellular processes, including RNA processing, degradation, and turnover. It plays a crucial role in regulating gene expression, controlling the lifespan of RNA molecules, and maintaining cellular homeostasis. The activity of ribonuclease A can be regulated by various factors, including pH, temperature, and the presence of inhibitors.'
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Proteins (3)

Compounds (6)