Which among the following are the substrates needed for purine salvage pathway?
High-Yield Explanation
Conversion of purines, their ribonucleosides, and their deoxyribonucleosides to mononucleotides involves "salvage reactions". The more impoant mechanism involves phosphoribosylation by PRPP of a free purine (Pu) to form a purine 5'-mononucleotide (Pu-RP). Phosphoryl transfer from ATP, catalyzed by adenosine- and hypoxanthine-phosphoribosyl transferases, conves adenine, hypoxanthine, and guanine to their mononucleotides. A second salvage mechanism involves phosphoryl transfer from ATP to a purine ribonucleoside. Phosphorylation of the purine nucleotides, catalyzed by adenosine kinase, conves adenosine and deoxyadenosine to AMP and dAMP. Similarly, deoxycytidine kinase phosphorylates deoxycytidine and 2'-deoxyguanosine, forming dCMP and dGMP. Ref: Rodwell V.W. (2011). Chapter 33. Metabolism of Purine & Pyrimidine Nucleotides. In D.A. Bender, K.M. Botham, P.A. Weil, P.J. Kennelly, R.K. Murray, V.W. Rodwell (Eds), Harper's Illustrated Biochemistry, 29e.