6UTB:
reference: The HIV-1 Env gp120 Inner Domain Shapes the Phe43 Cavity and the CD4 Binding Site., Prevost J, Tolbert WD, Medjahed H, Sherburn RT, Madani N, Zoubchenok D, Gendron-Lepage G, Gaffney AE, Grenier MC, Kirk S, Vergara N, Han C, Mann BT, Chenine AL, Ahmed A, Chaiken I, Kirchhoff F, Hahn BH, Haim H, Abrams CF, Smith AB 3rd, Sodroski J, Pazgier M, Finzi A, mBio. 2020 May 26;11(3). pii: mBio.00280-20. doi: 10.1128/mBio.00280-20. PMID: 32457241

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