Deoxyribonucleotides, which are dna precursors, are derived from ribonucleotides. ribonucleotide reductase catalyzes the conversion. answer the following five questions about ribonucleotide reductase.
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Since the 5 questions are not given, I am giving general information about RNR.
Ribonucleotide reductase (RNR), also known as ribonucleoside diphosphate reductase (rNDP), is an enzyme that catalyzes the formation of deoxyribonucleotides from ribonucleotides.
1. The substrates for RNR are ADP, GDP, CDP and UDP.
2. The end products of the ribonucleotide reductase reaction are the dNTPs. The substrates (ribonucleotides UDP, CDP, ADP, and GDP) are converted to dNTPs by a mechanism involving the generation of a free radical.
3. The reaction can be best described as - Hydrolysis. The first step involves the abstraction of the 3’- H of substrate 1 by radical Cys439. Subsequently, the reaction involves the elimination of one water molecule from carbon C-2’ of the ribonucleotide, catalyzed by Cys225 and Glu441. It involves the formation of a free radical.
4. The ultimate electron donor in the reaction is - NADPH. Electrons for the reduction reaction are supplied from NADPH via thioredoxin.
5. Thioredoxin donates electrons to the ribonucleotide reductase. Thioredoxin reductase is the enzyme that catalyzes the reduction of thioredoxin. Electrons are taken from NADPH via Thioredoxin reductase and are transferred to the active site of Thioredoxin, which goes on to reduce protein disulphides or other substrates.
Ribonucleotide reductase (RNR), also known as ribonucleoside diphosphate reductase (rNDP), is an enzyme that catalyzes the formation of deoxyribonucleotides from ribonucleotides.
1. The substrates for RNR are ADP, GDP, CDP and UDP.
2. The end products of the ribonucleotide reductase reaction are the dNTPs. The substrates (ribonucleotides UDP, CDP, ADP, and GDP) are converted to dNTPs by a mechanism involving the generation of a free radical.
3. The reaction can be best described as - Hydrolysis. The first step involves the abstraction of the 3’- H of substrate 1 by radical Cys439. Subsequently, the reaction involves the elimination of one water molecule from carbon C-2’ of the ribonucleotide, catalyzed by Cys225 and Glu441. It involves the formation of a free radical.
4. The ultimate electron donor in the reaction is - NADPH. Electrons for the reduction reaction are supplied from NADPH via thioredoxin.
5. Thioredoxin donates electrons to the ribonucleotide reductase. Thioredoxin reductase is the enzyme that catalyzes the reduction of thioredoxin. Electrons are taken from NADPH via Thioredoxin reductase and are transferred to the active site of Thioredoxin, which goes on to reduce protein disulphides or other substrates.
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