MBB 331 Study Guide - Midterm Guide: Dna Polymerase Iii Holoenzyme, Okazaki Fragments, Exonuclease

• School: Simon Fraser University
• Department: Molecular Biology and Biochemistry
• Course: MBB 331
• Professor: Jiarui Li

Document Summary

Meselson & stahl: dna replication is semi conservative. Bacteria: two bidirectional replication forks, theta-form replication, replication origin. Oric: five 9-mer dnaa-binding site, three 13-mer repeats (at rich) where dna is unwound. To isolate from particular organism, rst cut out bacterial origin in plasmid then re-insert fragment: cells that grow indicate that the newly inserted dna was the replicator. Replication fork is semi discontinuous: okazaki fragments on lagging strand, rna primers from primase. Quick stop mutant: ongoing replication machinery. Slow stop mutant: initiate dna replication. Dna pol has insertion site, post-insertion site. Processive: adds many dntps at once before releasing vs non-processive only adds one. Exonuclease: pol 1: 5"-3" exonuclease for nick translation, 3"-5- exonuclease for proofreading (most pol) Structure: palm holds dna, active site, most conserved, finger is for dntp incorporation. Closed: moves dntp to active-site cavity: incorrect base pairing does not t active site cavity, prevents closing, stalls replication. Gives time for dntp to be released and proofreading.