2BK9:
reference: Bishistidyl heme hexacoordination, a key structural property in Drosophila melanogaster hemoglobin., de Sanctis D, Dewilde S, Vonrhein C, Pesce A, Moens L, Ascenzi P, Hankeln T, Burmester T, Ponassi M, Nardini M, Bolognesi M, J Biol Chem. 2005 Jul 22;280(29):27222-9. Epub 2005 May 24. PMID: 15917230

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