Structural and functional characterizations of the G-quartet and i-motif elements in retinoblastoma susceptibility genes (Rb)
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Updated: Jul 18, 2026

Analysis of Cell Cycle Position in Mammalian Cells
Published on: January 21, 2012
1Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8501, Japan.
Abstract:
The thermal stability of a G-quartet formed by incorporation of 8-methylguanine (m8G) in the DNA sequence at the 5' terminus of the Rb gene was examined by CD melting experiments. Substitutions of m8G at positions that show syn conformations in antiparallel G-quartets stabilize the structure. Formation of the G-quartet structure in the Rb gene acts as a barrier in DNA synthesis, as determined using a rapid and simple polymerase arrest assay. It was found that the C-rich complementary strand could form an i-motif structure at lower pH values.
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