Representative multiple alignment of the ACRATA domain. It is viewed with the Belvu program . The colouring scheme indicates average BLOSUM62 score (correlated to amino acid conservation) in each alignment column: cyan (greater than 3), light red (between 3 and 1.5) and light green (between 1.5 and 0.5). The limits of the domains are indicated by the residue positions on each side. The TMHMM helix transmembrane [29, 30] consensus prediction is shown below the alignment. The asterisks above the alignment mark the conserved histidine residues mentioned in the text. Different groups of the ACRATA sequences are shown by coloured lines to the left of the alignment: red, YedZ family; yellow, STEAP family; violet, Nox family. The sequences are named with their swissprot or sptrembl identifiers, and also, if necessary, with their gene name. Species abbreviations: Homsa, Homo sapiens; Glovi, Gloeobacter violaceus; Anasp, Anabaena sp.; Cloac, Clostridium acetobutylicum; Musmu, Mus musculus; Xenla, Xenopus laevis; Sacce, Saccharomyces cerevisiae; Emeni, Emericella nidulans; Dicdi, Dictyostelium discoideum; Caeel, Caenorhabditis elegans; Drome, Drosophila melanogaster; Arath, Arabidopsis thaliana. Complementary information is accessible at: http://www.pdg.cnb.uam.es/STEAP.