Sequence alignment of THAP4 from Mus musculus (Q6P3Z3), THAP4 from Rattus norvegicus (Q642B6), THAP4 from Homo sapiens (Q8WY91), THAP4 from Callithrix jacchus (A6MKW1), THAP4 from Bos taurus (Q2TBI2), Nitrobindin from Arabidopsis thaliana (O64527), uncharacterized protein from Vitis vinifera (A5BBZ0), fatty acid-binding like protein from Mycobacterium smegmatis (A0R6J8), and fatty acid-binding like protein from Mycobacterium vanbaalenii (A1T297). Residues that are within 4 A of the bound heme of cTHAP4 are highlighted in green. The strictly conserved histidine that coordinates the heme is highlighted in red.