FIG 1.

Classification of 45 RHO enzymes. The phylogenetic tree, inferred by the neighbor-joining method, shows the relative positions of NidA and NidA3 among other RHOs based on the recent classification (25). Bootstrap values for 1,000 replicates are given. GeneID (GI) numbers were provided for RHO sequences whose detailed information can be found in the NCBI database. The bar indicates 10% sequence divergence. Underlining indicates the RHO systems from which the electron transport chain (ETC) components used in this study came.