Azathioprine is a drug that may be prescribed to transplant recipients to reduce the chance of tissue rejection reactions. in its active state, it acts as a purine analogue, inhibiting dna biosynthesis. this means that 6-mercaptopurine will be inserted in place of a purine containing nucleotides during dna replication. given this drug's mode of action, you would expect it to be incorporated into dna in place of:

Given this drug's mode of action, you would expect it to be incorporated into DNA in place of DNA sctructure.

Explanation:

Because the drug antagonizes purine metabolism and may inhibit synthesis of DNA, RNA,  and proteins. It may also interfere with cell's metabolism and inhibit mitosis. Its mechanism of action is lokely due to incorporation of thiopurine analogues into the DNA structure, causing chaim termination and cytotoxicity.

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