Phylogenetic analysis of thioredoxins similar to BC3987.

Bootstrap values obtained at a 50% consensus level using the Maximum Likelihood algorithm with 1000 replicates are shown at the branches of the tree. The evolutionary distances from the node separating the three clusters BC3987 homologs (in blue), Cp9 homologs (in green), and NrdH-redoxins (in red) are 0.47, 0.44, and 0.50 substitutions per site, respectively. Among the BC3987 homologs the active sites always have the -C-P-P-C- motif while the classical glutaredoxin active site motif -C-P-[YW]-C- is prevalent for the Cp9-like proteins. For the NrdH-redoxins, all encoded in a nrdHIEF operon, the predominant active site motif is -C-V-Q-C-. Alignment shown in Figure S1 (same color coding).