Nucleotidase

Content sourced from Wikipedia, licensed under CC BY-SA 3.0.

Nucleotidases are enzymes that break down nucleotides, the building blocks of DNA and RNA. They work by hydrolyzing a nucleotide to produce a nucleoside and a phosphate. For example, AMP becomes adenosine plus phosphate, and IMP or GMP become inosine or guanosine plus phosphate. This helps with digestion of nucleic acids and recycling nucleotides in cells.

There are two main types, depending on which end of the nucleotide they remove the phosphate from:

- 5′-nucleotidases (5′-nt): These remove the phosphate from the 5′ end. Some are attached to membranes and mainly act on AMP, aiding nucleotide salvage and participating in signaling through purinergic receptors. Others are soluble enzymes in the haloacid dehalogenase family, with several forms such as mdN (mitochondrial), cdN (cytosolic), and cytosolic nucleotidases named cN-I (AMP-preferring), cN-II (prefers IMP or GMP), and cN-III (a pyrimidine nucleotidase). A recently defined class is specific for IMP. 5′-nucleotidases have diverse roles, including cell–cell communication, DNA/RNA repair support, nucleotide salvage, signal transduction, and membrane transport.

- 3′-nucleotidases (3′-nt): These remove phosphate from the 3′ end of nucleotides.

Overall, nucleotidases come in many forms and locations, reflecting their roles in digestion, nucleotide metabolism, signaling, and maintaining nucleic acids.