3TTB:
reference: Comparative structural and functional analysis of two octaheme nitrite reductases from closely related Thioalkalivibrio species., Tikhonova T, Tikhonov A, Trofimov A, Polyakov K, Boyko K, Cherkashin E, Rakitina T, Sorokin D, Popov V, FEBS J. 2012 Aug 30. doi: 10.1111/j.1742-4658.2012.08811.x. PMID: 22935005

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