3VRG:
reference: Structures of haemoglobin from woolly mammoth in liganded and unliganded states., Noguchi H, Campbell KL, Ho C, Unzai S, Park SY, Tame JR, Acta Crystallogr D Biol Crystallogr. 2012 Nov;68(Pt 11):1441-9. doi:, 10.1107/S0907444912029459. Epub 2012 Oct 18. PMID: 23090393

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