1ZJ9:
reference: Siroheme- and [Fe4-S4]-dependent NirA from Mycobacterium tuberculosis is a sulfite reductase with a covalent Cys-Tyr bond in the active site., Schnell R, Sandalova T, Hellman U, Lindqvist Y, Schneider G, J Biol Chem 2005 Jul 22;280(29):27319-28. Epub 2005 May 24. PMID: 15917234

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