4. (25 pts) You are a member of alab studying DNA mismatch repair (MMR) in E.co.

Question

4. (25 pts) You are a member of alab studying DNA mismatch repair (MMR) in E.co.A fellow lab mate has designed several experiments to test aspects of the MMR pathway. Evaluate if their experiments will dedpher the MMR mechanism(s), and justify your answer to them (two sentences max for each) a. To test if strand discrimination is dependent on DNA methylation: "I will purify Muts,Mutl, and MutH, and add a piece of dsDNA with a mismatch purified from a DNA adenine methyltransferase b. To test if MMR is dependent on ATP "I will purify MutS, Mutl, and MutH, add them to a piece of DNA with a mismatch and GAmTC sequences, and see if the mismatch is repaired if 1 add a on hydrolysable ATP analogWhat will not occur in this situation? c To test if an interaction between MutS and Mutl. is required for MMR "Iwil purify Muts, Muth, and Mutl that has an amino acid mutation. will add these to DNA with a mismatch and GAmTC sequences

Explanation / Answer

a. The first procedure would work.

DNA has a repair mechanism which should not work if these repair proteins are purified.

Hence, mutations will occur in the next generations which can be observed.

b. The second procedure will also work.

DNA mismatch repair requires presence of ATP.

DNA mismatch repair will not occur if ATP is not supplied.

c. This procedure will also work

DNA mismatch repair requires co-ordination between MutS and MutL.

If defective MutL is added, mismatch repair cannot proceed

Related Questions

Navigate

• Browse (All)
• Browse 4
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.