APT1 (ADENINE PHOSPHORIBOSYL TRANSFERASE 1); adenine phosphoribosyltransferase; Adenosine phosphoribosyl transferase(E.C-2.4.2.7), involved in the one-step salvage of adenine to AMP. ; Catalyzes a salvage reaction resulting in the formation of AMP, that is energically less costly than de novo synthesis (243 aa)