The Chemical Reactions and Pathways Resulting in the Formation of a Purine Nucleotide a Compound Consisting of Nucleoside (a Purine Base Linked to a Deoxyribose or Ribose Sugar) Esterified with a Phosphate Group At Either the 3' or 5' Hydroxyl Group of the Sugar.
Interacting Selectively and Non Covalently with a Nucleotide Any Compound Consisting of a Nucleoside That Is Esterified with (ortho)phosphate or an Oligophosphate At Any Hydroxyl Group On the Ribose or Deoxyribose.
Catalysis of the Cleavage of C C C O C N and Other Bonds by Other Means Than by Hydrolysis or Oxidation or Conversely Adding a Group to a Double Bond. They Differ From Other Enzymes in That Two Substrates Are Involved in One Reaction Direction But Only One in the Other Direction. When Acting On the Single Substrate a Molecule Is Eliminated and This Generates Either a New Double Bond or a New Ring.