6JKN:
reference: The crystal structure of an antiparallel chair-type G-quadruplex formed by Bromo-substituted human telomeric DNA., Geng Y, Liu C, Zhou B, Cai Q, Miao H, Shi X, Xu N, You Y, Fung CP, Din RU, Zhu G, Nucleic Acids Res. 2019 Apr 8. pii: 5430838. doi: 10.1093/nar/gkz221. PMID: 30957851

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