GENE 540 Study Guide - Midterm Guide: Dna Replication, Rad51, Dna Ligase
Document Summary
Once the fork moves the left if there is a single strand break up ahead, when it is separated, the strand will dissociate and the daughter strand would not be generated. So the replication site is moving to the right, and once it reaches the dna nick, one of the strand dissociates (now you have separation of the strands) Then dna ligase first comes in and closes the gap on one of the strands (longer one); the other smaller strand is just chilling on the side. Then you have 5"-exonuclease that acts on the broken end it digests some bases; by doing this, now you have a free 3" end. Reca/rad51 have taken the open 3-oh end after the second step and caused an invasion. After the invasion, these proteins are capable of moving the structure along the dna (requires atp) Reca or rad51 is also capable of moving the structure. The resulting structure is called a holliday structure.
