BIOL3190 Lecture Notes - Lecture 4: Dna Mismatch Repair, Pyrimidine Dimer, Xeroderma Pigmentosum
Document Summary
So many ways to chemically mess up dna along the repair pathways. The enzymes that are going to fix it are going to recognize the problem and bind to it. Because all the different problems have a dif chemical structure you need dif proteins and pathways to resolve the problems. Specifically for dealing with #1 source of mutation (replication) Each time the genome is replicated you are at risk of introducing changes to the sequence. If dna polymerase messes up and it puts a g across from an a, you would call it a mismatch. Not really a mutation yet, no one is in charge (a or g) It"s supposed to (cid:396)e(cid:272)og(cid:374)ize the (cid:373)is(cid:373)at(cid:272)h a(cid:374)d (cid:396)epla(cid:272)e it. (cid:448)e(cid:396)(cid:455) lo(cid:449) statisti(cid:272)all(cid:455) a(cid:373)ou(cid:374)t of ti(cid:373)es it does(cid:374)"t (cid:272)at(cid:272)h it and that is where the mutation is. Because our genome is so huge, everytime our dna replicates, a mismatch happens (so many chances) Deals with larger excisions like for the thymine dimers.
