GMP synthase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: ATP + XMP + NH4(+) = AMP + diphosphate + GMP + 2H+. [RHEA:18301]

GMP synthase is an enzyme that catalyzes the formation of guanosine monophosphate (GMP) from xanthosine monophosphate (XMP) and glutamine. This reaction is essential for the biosynthesis of guanine nucleotides, which are crucial components of DNA, RNA, and other important cellular molecules. GMP synthase activity involves two distinct steps:

1. **XMP amidation:** Glutamine is used as an amino donor to convert XMP to xanthylate. This reaction is catalyzed by the glutamine amidotransferase domain of GMP synthase.
2. **Xanthylate reduction:** The xanthylate is then reduced to GMP using NADPH as a reducing agent. This reaction is catalyzed by the reductase domain of GMP synthase.

The reaction mechanism of GMP synthase is highly conserved across species. It involves a series of complex interactions between the enzyme, substrates, and cofactors. The glutamine amidotransferase domain of GMP synthase utilizes a mechanism involving a covalent intermediate, while the reductase domain employs a ping-pong mechanism.

GMP synthase activity is regulated by a variety of factors, including the levels of guanine nucleotides, the availability of substrates, and the activity of other enzymes involved in purine biosynthesis. Mutations in the GMP synthase gene can lead to various genetic disorders affecting purine metabolism.

Overall, GMP synthase plays a vital role in purine nucleotide biosynthesis, ensuring the proper functioning of a wide range of cellular processes. Its activity is finely regulated to maintain the appropriate levels of GMP and other guanine nucleotides within the cell.'
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Proteins (1)

Compounds (2)