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What is Which among the following are the substrates needed for purine salvage pathway? and explain in detail?
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.