Aspartate—ammonia ligase explained

Aspartate—ammonia ligase
Ec Number:	6.3.1.1
Cas Number:	9023-69-2
Go Code:	0004071

In enzymology, an aspartate—ammonia ligase is an enzyme that catalyzes the chemical reaction

ATP + L-aspartate + NH₃

\rightleftharpoons AMP + diphosphate + L-asparagine

The 3 substrates of this enzyme are ATP, L-aspartate, and NH₃, whereas its 3 products are AMP, diphosphate, and L-asparagine.

This enzyme belongs to the family of ligases, specifically those forming carbon-nitrogen bonds as acid-D-ammonia (or amine) ligases (amide synthases). The systematic name of this enzyme class is L-aspartate:ammonia ligase (AMP-forming). Other names in common use include asparagine synthetase, and L-asparagine synthetase. This enzyme participates in 3 metabolic pathways: alanine and aspartate metabolism, cyanoamino acid metabolism, and nitrogen metabolism.

Structural studies

As of late 2007, two structures have been solved for this class of enzymes, with PDB accession codes and .

References

• RAVEL JM, NORTON SJ, HUMPHREYS JS, SHIVE W . 1962 . Asparagine biosynthesis in Lactobacillus arabinosus and its control by asparagine through enzyme inhibition and repression . J. Biol. Chem. . 237 . 2845 - 9 . 14490631 .
• Webster GC, Varner JE . 1955 . Aspartate metabolism and asparagine synthesis in plant systems . J. Biol. Chem. . 215 . 91 - 99 . 14392145.