6L1Y:
reference: A non-canonical binding interface in the crystal structure of HIV-1 gp120 core in complex with CD4., Duan LW, Zhang H, Zhao MT, Sun JX, Chen WL, Lin JP, Liu XQ, Sci Rep. 2017 Apr 21;7:46733. doi: 10.1038/srep46733. PMID: 28429756

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