Formation of parallel four-stranded complexes by guanine-rich motifs in DNA and its implications for meiosis.
We have discovered that single-stranded DNA containing short guanine-rich motifs will self-associate at physiological salt concentrations to make four-stranded structures in which the strands run in parallel fashion. We believe these complexes are held together by guanines bonded to each other by Hoogsteen pairing. Such guanine-rich sequences occur in immunoglobulin switch regions, in gene promoters, and in chromosomal telomeres. We speculate that this self-recognition of guanine-rich motifs of DNA serves to bring together, and to zipper up in register, the four homologous chromatids during meiosis.
Sen
D
D
Department of Cellular and Developmental Biology, Harvard University, Cambridge, Massachusetts 02138.
Gilbert
W
W
D001483:Base Sequence; D004277:DNA, Single-Stranded / Q000032:analysis*; D006147:Guanine / Q000378:metabolism*; D008540:Meiosis; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation
D004277:DNA, Single-Stranded; D006147:Guanine