Page last updated: 2024-10-24

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)

ProteinDefinitionTaxonomy
Ribonuclease pancreaticA protein that is a translation product of the RNASE1 gene in cow. [PRO:DNx, UniProtKB:P61823]Bos taurus (cattle)
Seminal ribonucleaseA protein that is a translation product of the SRN gene in cow. [PRO:DNx, UniProtKB:P00669]Bos taurus (cattle)
Ribonuclease pancreaticA ribonuclease pancreatic that is encoded in the genome of human. [PRO:DNx, UniProtKB:P07998]Homo sapiens (human)

Compounds (6)

CompoundDefinitionClassesRoles
uridine diphosphateUridine Diphosphate: A uracil nucleotide containing a pyrophosphate group esterified to C5 of the sugar moiety.pyrimidine ribonucleoside 5'-diphosphate;
uridine 5'-phosphate
Escherichia coli metabolite;
mouse metabolite
cytidine monophosphatecytidine 5'-monophosphate : A pyrimidine ribonucleoside 5'-monophosphate having cytosine as the nucleobase.

Cytidine Monophosphate: Cytidine (dihydrogen phosphate). A cytosine nucleotide containing one phosphate group esterified to the sugar moiety in the 2', 3' or 5' position.
cytidine 5'-phosphate;
pyrimidine ribonucleoside 5'-monophosphate
Escherichia coli metabolite;
human metabolite;
mouse metabolite
camptothecinNSC 100880: carboxylate (opened lactone) form of camptothecin; RN refers to (S)-isomer; structure given in first sourcedelta-lactone;
pyranoindolizinoquinoline;
quinoline alkaloid;
tertiary alcohol
antineoplastic agent;
EC 5.99.1.2 (DNA topoisomerase) inhibitor;
genotoxin;
plant metabolite
3'-cmp3'-CMP : A cytidine 3'-phosphate compound with a monophosphate group at the 3'-position.cytidine 3'-phosphate;
pyrimidine ribonucleoside 3'-monophosphate
Escherichia coli metabolite;
metabolite;
mouse metabolite
adenosine-5'-carboxylic acidpurine nucleoside
3'-uridylic acid3'-UMP : A pyrimidine ribonucleoside 3'-monophosphate having uracil as the nucleobase.

3'-uridylic acid: structure in first source; main heading URIDINE MONOPHOSPHATE refers to 5'-uridylic acid
pyrimidine ribonucleoside 3'-monophosphate;
uridine phosphate
Escherichia coli metabolite