title: Non-B DNA structure-induced genetic instability.
abstract: Repetitive DNA sequences are abundant in eukaryotic genomes, and many of these sequences have the potential to adopt non-B DNA conformations. Genes harboring non-B DNA structure-forming sequences increase the risk of genetic instability and thus are associated with human diseases. In this review, we discuss putative mechanisms responsible for genetic instability events occurring at these non-B DNA structures, with a focus on hairpins, left-handed Z-DNA, and intramolecular triplexes or H-DNA. Slippage and misalignment are the most common events leading to DNA structure-induced mutagenesis. However, a number of other mechanisms of genetic instability have been proposed based on the finding that these structures not only induce expansions and deletions, but can also induce DNA strand breaks and rearrangements. The available data implicate a variety of proteins, such as mismatch repair proteins, nucleotide excision repair proteins, topoisomerases, and structure specific-nucleases in the processing of these mutagenic DNA structures. The potential mechanisms of genetic instability induced by these structures and their contribution to human diseases are discussed.
authors.affiliation: Department of Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park-Research Division, 1808 Park Road 1-C, P.O. Box 389, Smithville, 78957, USA.
authors.forename: Guliang
authors.initials: G
authors.lastname: Wang
authors.forename: Karen M
authors.initials: KM
authors.lastname: Vasquez
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D042822:Genomic Instability; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D004247:DNA