Guanine-rich telomeric sequences stimulate DNA polymerase activity in vitro

Guanine-rich oligonucleotides and short telomeric DNA sequences can self-as sociate into G-quartet stabilized complexes. We discovered that this self-a ssociation can occur in sequencing reactions and that higher-order structur es stimulate DNA polymerase to synthesize extended DNA strands. Base analog ues were used to identify Hoogsteen base pairings as stabilizing forces in these stimulatory DNA structures. Scanning force microscopy confirmed that quartet-DNA was formed from these oligomers and that these extended, four-s tranded structures could be bound by DNA polymerase. Since guanine quartet- stabilized structures are proposed to exist in vivo, such structures may st imulate DNA polymerization in vivo.