EC 6.3 Forming carbon-nitrogen bonds

This subclass contains enzymes that form carbon-nitrogen bonds. Sub-subclasses are: acid—ammonia (or amine) ligases (amide synthases; EC 6.3.1), acid—amino-acid ligases (peptide synthases; EC 6.3.2), enzymes forming heterocyclic rings (cyclo-ligases; EC 6.3.3), enzymes using glutamine as amido-N-donor (EC 6.3.5) and other carbon-nitrogen ligases (EC 6.3.4).