MIMM 211 Lecture Notes - Lecture 13: Dna Polymerase Iii Holoenzyme, Dna Mismatch Repair, Dna Repair
13 Dec 2018
School
Department
Course
Professor
Document Summary
These two enzymes follow the replication fork on the newly synthesised dsdna and scan for mismatches. Bacterial cells methylate their dna which is useful for different molecular mechanisms. Note that there is a moment in time where the parental strand will be methylated but the new strand will not be this is how the enzymes can tell which strand is which. The enzymes know that the wrong nt is the one that is not methylated. When muts and mutl recognise mismatches, they recruit muth which looks at the dna and cuts the non-methylated strand degradation of the cut strand by exonuclease i in the. 5" to 3" direction dna pol iii will resynthesize the dna. **when only one strand is methylated = hemi-methylated. Uvrab scans the dna looking for damage in the dna or distortion of the helix (via crosslinking etc) When damage is found, uvra is released and uvrb remains associated with the damaged region.
