title: DNA structure and function.
abstract: The proposal of a double-helical structure for DNA over 60 years ago provided an eminently satisfying explanation for the heritability of genetic information. But why is DNA, and not RNA, now the dominant biological information store? We argue that, in addition to its coding function, the ability of DNA, unlike RNA, to adopt a B-DNA structure confers advantages both for information accessibility and for packaging. The information encoded by DNA is both digital - the precise base specifying, for example, amino acid sequences - and analogue. The latter determines the sequence-dependent physicochemical properties of DNA, for example, its stiffness and susceptibility to strand separation. Most importantly, DNA chirality enables the formation of supercoiling under torsional stress. We review recent evidence suggesting that DNA supercoiling, particularly that generated by DNA translocases, is a major driver of gene regulation and patterns of chromosomal gene organization, and in its guise as a promoter of DNA packaging enables DNA to act as an energy store to facilitate the passage of translocating enzymes such as RNA polymerase.
authors.affiliation: MRC Laboratory of Molecular Biology, Cambridge, UK.|Department of Biochemistry, University of Cambridge, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Travers
authors.affiliation: Jacobs University Bremen, Germany.
authors.forename: Georgi
authors.initials: G
authors.lastname: Muskhelishvili
mesh_terms: D000818:Animals; D042002:Chromatin Assembly and Disassembly; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D004278:DNA, Superhelical / Q000737:chemistry / Q000378:metabolism; D004734:Energy Metabolism; D055614:Genetic Phenomena; D005823:Genetics / Q000266:history*; D016678:Genome; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D009690:Nucleic Acid Conformation
chemical_list: D004278:DNA, Superhelical; D004247:DNA
keywords: A-DNA; B-DNA; DNA as an energy store; DNA backbone conformation; DNA elasticity; DNA information; DNA structure; DNA topology; alternative DNA structures; genome organisation