title: Transcription-associated mutagenesis.
abstract: Transcription requires unwinding complementary DNA strands, generating torsional stress, and sensitizing the exposed single strands to chemical reactions and endogenous damaging agents. In addition, transcription can occur concomitantly with the other major DNA metabolic processes (replication, repair, and recombination), creating opportunities for either cooperation or conflict. Genetic modifications associated with transcription are a global issue in the small genomes of microorganisms in which noncoding sequences are rare. Transcription likewise becomes significant when one considers that most of the human genome is transcriptionally active. In this review, we focus specifically on the mutagenic consequences of transcription. Mechanisms of transcription-associated mutagenesis in microorganisms are discussed, as is the role of transcription in somatic instability of the vertebrate immune system.
authors.affiliation: Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710; email: sue.robertson@duke.edu.
authors.forename: Sue
authors.initials: S
authors.lastname: Jinks-Robertson
authors.forename: Ashok S
authors.initials: AS
authors.lastname: Bhagwat
mesh_terms: D001419:Bacteria; D004249:DNA Damage / Q000235:genetics; D004261:DNA Replication / Q000235:genetics*; D004277:DNA, Single-Stranded / Q000235:genetics; D006801:Humans; D016296:Mutagenesis / Q000235:genetics*; D004718:Saccharomycetales / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D004277:DNA, Single-Stranded
keywords: DNA damage; class-switch recombination; cytosine deamination; somatic hypermutation; topoisomerase