2DV6:
reference: Structure and function of a hexameric copper-containing nitrite reductase., Nojiri M, Xie Y, Inoue T, Yamamoto T, Matsumura H, Kataoka K, Deligeer, Yamaguchi K, Kai Y, Suzuki S, Proc Natl Acad Sci U S A. 2007 Mar 13;104(11):4315-20. Epub 2007 Mar 5. PMID: 17360521

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