Labeled and annotated multiple sequence alignment of COQ7. Amino acid sequences of COQ7 were analyzed as described in Materials and Methods and include Homo sapiens (NCBI accession number NP_057222.2) and homologs in Saccharomyces cerevisiae (NP_014768.2), Schizosaccharomyces pombe (NP_595416), Pseudomonas aeruginosa (QLJ91605.1), Rickettsia prowazekii (ADE29699), Drosophila melanogaster (NP_651967.2), Caenorhabditis elegans (NP_498128.1), Danio rerio (NP_001076480.1), and Mus musculus (NP_034070.1). See KEY for descriptions of the figure annotations. The COQ9 interfacing loop is boxed in cyan, data from [50]. Residues that ligand iron 1 are marked with blue dots, and those that ligand iron 2 are marked with orange dots, data from [52]. COQ7-COQ9 interacting residues are marked with purple dots, data from [50,52].