6IRG:
reference: Structural Basis of the Proton Sensitivity of Human GluN1-GluN2A NMDA Receptors., Zhang JB, Chang S, Xu P, Miao M, Wu H, Zhang Y, Zhang T, Wang H, Zhang J, Xie C, Song N, Luo C, Zhang X, Zhu S, Cell Rep. 2018 Dec 26;25(13):3582-3590.e4. doi: 10.1016/j.celrep.2018.11.071. PMID: 30590034

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