BIOL308 Study Guide - Final Guide: Dna Polymerase Iii Holoenzyme, Dna Polymerase I, Okazaki Fragments
9 Dec 2016
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Document Summary
List proteins (enzymes and other factors) involved in the process of dna replication in e. coli. Explain the role of each of these proteins in replication. Dnaa: initiation of replication at oric by recognizing 4 dna boxes(9-mers) which together with 10-20 dnaa proteins form an initial complex. Dnab (helicase): moves along dsdna and separates strands (w/ atp). In e. coli is a hexamer that clamps around any 2 ssdna and moves towards the duplex region of the replication fork. Dnac: clamp loader protein that escorts dnab to the right spot to form pre-priming complex. Single stranded binding proteins: stabilizes structures by binding ssdna, participates in cooperative binding where 1 molecule promotes the binding of the next, straightening the molecules; prevents internal pairing and double helix from reforming. Topoisomerase ii (gyrase): nicks the dsdna strand to convert (+) supercoils at the replication fork to (-) supercoils, forms negative supercoils at the oric so replication can be initiated by dnaa.
