(Solved): Why are PRPP (5-Phosphoribosyl 1-pyrophosphate inhibited by purine bases (A and G)? also, how? ...

Why are PRPP (5-Phosphoribosyl 1-pyrophosphate inhibited by purine bases (A and G)? also, how?

Common aspects of purines and pyrimidine synthesis - Bases are synthesized in the ribose form (to be used in transcription) - Bases can be converted to the deoxy form (for DNA replication) - Ribonucleotide reductase converts ribose bases $$?$$ deoxybases - Enzyme is only active when DNA replication is occurring. - The enzyme has two sites for regulation - Enzyme activity site (allosteric) $$?$$ must have ATP/ADP bound for the enzyme to be active - Substrate specificity site (effector) $$?$$ the enzyme will preferentially convert specific nucleotides depending on what base is bound to this site - Synthesis of 5-phosphoribosyl 1-pyrophosphate (PRPP) 0 This is the conversion of ribose 5 -phosphate $$?$$ PRPP by the enzyme PRPP synthetase - Reaction is inhibited by purine bases ( $$A$$ and $$G$$ ) - PRPP will be the active 5-carbon sugar used for the synthesis of both purines and pyrimidines