1HDA:
reference: A novel allosteric mechanism in haemoglobin. Structure of bovine deoxyhaemoglobin, absence of specific chloride-binding sites and origin of the chloride-linked Bohr effect in bovine and human haemoglobin., Perutz MF, Fermi G, Poyart C, Pagnier J, Kister J, J Mol Biol 1993 Oct 5;233(3):536-45. PMID: 8411160

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