G-Quadruplexes
Guanine-rich DNA sequences of a particular form have the ability to fold into 4-stranded structures called G-quadruplexes. ~ English chemist Julian Huppert & Indian chemist Shankar Balasubramanian
DNA is typically a double-stranded helix, coiling into densely packed chromosomes. But a strand may double up, particularly at telomeres, which are rich in guanine.
Via hydrogen bonds, G-rich strands naturally self-associate into G-quadruplexes. These squarish 4-strand DNA structures act in various cellular pathways, including gene expression, DNA replication, and telomere maintenance. As an aberration, G-quadruplexes are instrumental in cancer.
