1GS6:
reference: Biochemical and crystallographic studies of the Met144Ala, Asp92Asn and His254Phe mutants of the nitrite reductase from Alcaligenes xylosoxidans provide insight into the enzyme mechanism., Ellis MJ, Prudencio M, Dodd FE, Strange RW, Sawers G, Eady RR, Hasnain SS, J Mol Biol 2002 Feb 8;316(1):51-64. PMID: 11829502

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