BIO206H5 Lecture Notes - Lecture 16: Okazaki Fragments, Dna Replication, Replisome
Document Summary
Remember that dna pol requires a double stranded nucleic acid to bind. Dna helicase is a homohexomeric protein that is an atp driven dna helices. It uses atp to unwind dna double strand. The action of this dna helices results in the super coiling of the dna. In the case e. coli, there"s an important topoisomerase called dna gyros. These topoisomerase are called endonuclease because on of their functions is they cut dna. The cutting allows for the relief of the supercoiling tension that is created as the dna pushes on the helices so it can reanneal. Those cuts are only transient, the 3 prime to 5 prime phosphodiester bonds that are cut by the topoisomerases are reformed again. Stand at top of pic is leading strand. That rna segment is about 10 nucleotides in length. Clamp loader in the presence of atp and a 2 halves of a sliding clamp protein assembly eon this double stranded nucleic acid.
