CEM 311 Lecture Notes - Lecture 58: Frameshift Mutation, Pyrimidine Dimer, Dna Mismatch Repair
Document Summary
Base analogs similar enough to the proper bases to get taken up by the cells, converted into nucleotide triphosphates, and incorporated during replication. Because of the structural similarity to the normal bases, this will lead to frequent mistakes during replication process. The enol form can base pair with guanine. Translation dna synthesis: replication errors, pyrimidine dimers, damaged base, pyrimidine dimer: bulky adduct base, ds breaks, pyrimidine dimer, apurinic site, bulky adduct base. Two separate enzymes that catalyze repair of cpds (cyclobutane pyrimidine dimer) Uses energy from near-uv to blue light to break bonds holding 2 pyrimidines together. Gg-ner (global genome): 25 or more proteins involved. Complex composed of xpc (equivalent to uvra) and hhr23b initiates repair binding lesion in the genome, which causes limited amount of dna melting. Tc-ner (transcription-coupled repair): involves recruitment to rna polymerase of nucleotides excision repair proteins. Rna polymerase plays role of xpc in damage sensing and initial dna melting.
