"ATP bound to the substrate site activates the reduction of pyrimidines (CDP and UDP) to form deoxycytidine diphosphate (dCDP) and deoxyuridine diphosphate (dUDP). The dUDP is not used for DNA synthesis; rather, it is used to produce deoxythymidine monophosphate (dTMP). Once dTMP is produced, it is phosphorylated to dTTP, which then binds to the substrate site and induces the reduction of GDP. As dGTP accumulates, it replaces dTTP in the substrate site and allows ADP to be reduced to deoxyadenosine diphosphate (dADP). This leads to the accumulation of dATP, which inhibits the overall activity of the enzyme."
Table showing Regulation of ribonucleotide reductase
QUESTIONS:
1. How do I know whether CDP or UDP is the preferred substrate, since they both require ATP or dATP?
2. dUDP is not used for DNA synthesis, because it's uridine based which is RNA base, correct? But why does it become a monophosphate - dTMP?
3. What is phosphorylating dTTP and induces the reduction of GDP?
3. Why is GDP becoming dGTP - does GDP become dGTP when it is reduced? so phosphorylation is a reduction step? I thought the reduction was the removal of the hydroxyl from the rbinucleotide?
4. Is dGTP reducing ADP to dADP? What is reducing ADP? Ribonucleotide reductase + thioredoxin?
5. Does this only happen in this order? dCDP = dUDP -> dGDP -> dATP -> accumulation/inhibition of activity?
Can anyone help me understand this a little bit better please?
Table showing Regulation of ribonucleotide reductase
QUESTIONS:
1. How do I know whether CDP or UDP is the preferred substrate, since they both require ATP or dATP?
2. dUDP is not used for DNA synthesis, because it's uridine based which is RNA base, correct? But why does it become a monophosphate - dTMP?
3. What is phosphorylating dTTP and induces the reduction of GDP?
3. Why is GDP becoming dGTP - does GDP become dGTP when it is reduced? so phosphorylation is a reduction step? I thought the reduction was the removal of the hydroxyl from the rbinucleotide?
4. Is dGTP reducing ADP to dADP? What is reducing ADP? Ribonucleotide reductase + thioredoxin?
5. Does this only happen in this order? dCDP = dUDP -> dGDP -> dATP -> accumulation/inhibition of activity?
Can anyone help me understand this a little bit better please?
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