Question

Refer to Animation: Base Excision Repair. In the example in the animation, uracil is incorrectly paired with guanine. What is the effect on the DNA sequence if base excision repair does not remove the uracil and DNA replication is allowed to proceed?

Answer 1

Mutation will occur

Explanation:

Base excision repair operates for small DNA damage such as deaminated bases

• DNA glycosylase plays an important role in cleavage of glycosidic bond of abnormal base (does not cleave phosphodiester bond)
• Uracil is incorrectly paired with guanine then mutation will occur
• The original GC base pair will change into AT base pair(transition of GC to AT)
• Transition is a mutation in which one purine(adenine or guanine) is substituted for other or one pyrimidine(cytosine or thymine or uracil) is substituted for other