Ribose 5 phosphate—ammonia ligase

In enzymology, a ribose-5-phosphate-ammonia ligase (EC 6.3.4.7) is an enzyme that catalyzes the chemical reaction

The 3 substrates of this enzyme are ATP, ribose 5-phosphate, and NH₃, whereas its 3 products are ADP, phosphate, and 5-phosphoribosylamine.

This enzyme belongs to the family of ligases, specifically those forming generic carbon-nitrogen bonds. The systematic name of this enzyme class is ribose-5-phosphate:ammonia ligase (ADP-forming). Other names in common use include 5-phosphoribosylamine synthetase, ribose 5-phosphate aminotransferase, and ammonia-ribose 5-phosphate aminotransferase. This enzyme participates in purine metabolism.