11:680:101 Study Guide - Final Guide: Dna Gyrase, Dna Replication, Tata Box
Document Summary
Chapter 8 archaeal and eukaryotic molecular biology. Archaeal forms clusters of 4 instead of 8 and accommodate approximately 80 base pairs. They are shorter, but are homologous in amino acid sequence and similar in their three-dimensional structure: histones fold; the central region of the histone protein that is necessary for forming nucleosomes. Supercoiling by gyrase: some archaea use dna gyrase to package their dna by supercoiling, they are sensitive to antibiotics that act by inhibiting dna gryase quinolones, novobiocin. Reverse gyrase in hyperthermophiles: achaeal that grow at extremely high temperatures have this enzyme. It is a topoisomerase that introduces positive supercoils into the dna which helps prevent denaturation by heat: genetic information in dna must be assessable to the cell"s replication and transcriptional machinery. Therefore, whether supercoiling is controlled by the activity of dna gyrase or reverse gyrase, the structure of dna within the cell likely remain quiet dynamic.
