FIG. 5.

Multiple sequence analysis of SoxX proteins. The amino terminus of the mature R. sulfidophilum SoxX protein determined by protein sequencing is given in the line labeled “N-terminus.” Experimentally determined (R. sulfidophilum and P. pantotrophus) or predicted SoxX signal peptides are underlined. The consensus c-type cytochrome Cys-Xaa-Xaa-Cys-His heme attachment site and the proposed methionine distal heme iron ligand are boxed. The sources of the sequence data are as for Fig. 3. The numbering on the individual sequences refers to the mature protein.