Ornithine cyclodeaminase

In enzymology, an ornithine cyclodeaminase is an enzyme that catalyzes the chemical reaction


 * L-ornithine $$\rightleftharpoons$$ L-proline + NH3

Hence, this enzyme has one substrate, L-ornithine, and two products, L-proline and NH3.

This enzyme belongs to the family of lyases, specifically ammonia lyases, which cleave carbon-nitrogen bonds. The systematic name of this enzyme class is L-ornithine ammonia-lyase (cyclizing; L-proline-forming). Other names in common use include ornithine cyclase, ornithine cyclase (deaminating), and L-ornithine ammonia-lyase (cyclizing). This enzyme participates in arginine and proline metabolism. It employs one cofactor, NAD+.

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