5ZK8:
reference: Structural insights into the subtype-selective antagonist binding to the M2 muscarinic receptor., Suno R, Lee S, Maeda S, Yasuda S, Yamashita K, Hirata K, Horita S, Tawaramoto MS, Tsujimoto H, Murata T, Kinoshita M, Yamamoto M, Kobilka BK, Vaidehi N, Iwata S, Kobayashi T, Nat Chem Biol. 2018 Dec;14(12):1150-1158. doi: 10.1038/s41589-018-0152-y. Epub, 2018 Nov 12. PMID: 30420692

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