6D2U:
reference: An ultra-high affinity ligand of HIV-1 TAR reveals the RNA structure recognized by P-TEFb., Shortridge MD, Wille PT, Jones AN, Davidson A, Bogdanovic J, Arts E, Karn J, Robinson JA, Varani G, Nucleic Acids Res. 2018 Nov 27. pii: 5210372. doi: 10.1093/nar/gky1197. PMID: 30481318

This OCA Structure page
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