This domain can be found in THAP4 from mammals and At1g79260 from Arabidopsis. THAP4 catalyzes the heme-based conversion of peroxynitrite into nitrate-NO3- in vitro [1]. At1g79260 is a nitrophorin-like heme-binding protein that may reversibly bind nitric oxide (NO) and be involved in NO transport [2]. This entry also includes the beta-barrel domain of Caenorhabditis elegans protein male abnormal 7 (Mab-7) which plays an important role in determining body shape and sensory ray morphology [3]. Nitrobindins (Nbs), constituting a heme-protein family spanning from bacteria to Homo sapiens, display an all-beta-barrel structural organisation. Proteins containing this domain are putatively related to fatty acid-binding proteins (FABPs) [4].

1: Human nitrobindin: the first example of an all-beta-barrel ferric heme-protein that catalyzes peroxynitrite detoxification. De Simone G, di Masi A, Polticelli F, Ascenzi P; FEBS Open Bio. 2018;8:2002-2010. PMID:30524950

2: The structure and NO binding properties of the nitrophorin-like heme-binding protein from Arabidopsis thaliana gene locus At1g79260.1. Bianchetti CM, Blouin GC, Bitto E, Olson JS, Phillips GN Jr; Proteins. 2010;78:917-931. PMID:19938152

3: mab-7 encodes a novel transmembrane protein that orchestrates sensory ray morphogenesis in C. elegans. Tsang SW, Nguyen CQ, Hall DH, Chow KL; Dev Biol. 2007;312:353-366. PMID:17959165

4: The crystal structure of Rv0813c from Mycobacterium tuberculosis reveals a new family of fatty acid-binding protein-like proteins in bacteria. Shepard W, Haouz A, Grana M, Buschiazzo A, Betton JM, Cole ST, Alzari PM; J Bacteriol. 2007;189:1899-1904. PMID:17172346