Uridylyl Transferase

Uridylyl transferase is an enzyme that uridylates (puts a uridyl group onto) the regulatory protein, P II (Figure 20.9). P II forms a complex with the enzyme, adenylyl transferase (AT), forming an AT-P II complex. When P II is uridylated, the AT-P II complex catalyzes deadenylylation of glutamine synthetase. This, in turn, causes glutamine synthetase to become active. Conversely, when P II is deuridylated (by a different enzyme), the AT-P II complex catalyzes deadenylylation of glutamine synthetase, inactivating it.

See also: Utilization of Ammonia, ,