1W7O:
reference: Proton-assisted two-electron transfer in natural variants of tetraheme cytochromes from Desulfomicrobium Sp., Correia IJ, Paquete CM, Coelho A, Almeida CC, Catarino T, Louro RO, Frazao C, Saraiva LM, Carrondo MA, Turner DL, Xavier AV, J Biol Chem. 2004 Dec 10;279(50):52227-37. Epub 2004 Sep 28. PMID: 15456779

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