The actinobacterial Rieske proteins. Protein sequence alignments of the Rieske iron-sulfur proteins from different bacteria. Proteins were aligned using ClustalW and GENEDOC. The longer Rieske iron-sulfur proteins of actinobacterial representatives C. glutamicum (Coryne), M. tuberculosis (Myco), and S. coelicolor (Strep) are aligned alongside the well-characterized Rieske proteins of Paracoccus denitrificans (Para) and Rhodobacter sphaeroides (Rhodo). Transmembrane domains (TMD) were predicted using TM2HMM (http://www.cbs.dtu.dk/services/TMHMM/) and are marked in red above the alignment. The consensus twin arginine (Tat) motif is highlighted in green and a KR motif in front of the first predicted TMD is indicated in blue. Conserved boxes I and II that coordinate the 2Fe-2S cluster are highlighted in yellow. The arrow indicates the position after which the reporter proteins MBP or AmiA were fused. The differences in shading (from gray to black) refer to the level of amino acid conservation between the different species (with black indicating absolute conversion).