A schematic figure showing the architectures of proteins containing b5-domains. The order of the proteins in this illustration is the same as in Figure 1, except that, for proteins with a similar architecture, only one example is shown. All domain names correspond to homonymous Pfam-A families, except for the MYSc domain, which is a SMART database entry . The black rectangles represent inter-domain transmembrane regions predicted by TMHMM . The heme_1 domain corresponds closely to the b5-domain aligned in Figure 1. More information about each of the domains can be found in the Pfam database [18,19].