Phylogenetic analysis and genome organization of tatABC genes.

(A) Left side panel: Phylogenetic tree construction using neighbor-joining method (NJ-JTT, 1000 bootstrap) with MEGA.4 of 53 bacterial species based on the concatenated alignment of 11 conserved proteins (RNA Pol ß and ß′, alanyl-tRNA synthetase, phenylalanyl-tRNA synthetase, arginyl-tRNA synthetase, EF-Tu, EF-G, RecA, GyrA, Gyrß, Hsp70). Right side panel: Genome organization of tatABC genes. (B) tatA, tatB and tatC genes in Anaplasma marginale str. St. Maries, and Brucella melitensis biovar abortus 2308 (Chr I) were displayed and visualized with the Circular Genome Viewer (CGView). Orthologs genes for tatA, tatB and tatC were found in almost all the genomes studied, with the exception of species analyzed from the genera Rickettsia, Neorickettsia, Orientia and Wolbachia that lacked the tatB gene. Three different main organizations according to operon structure preservation were found; one with the commonly described operon organization, another one with a partially dispersed organization (tatA locus maps in a different location from that of the tatBC operon in the same strand), and a completely scattered distribution for tat genes in well-separated location of the circular genomes in several genera of the order Rickettsiales. Organisms lacking a tatB homolog, with the exception of Neorickettsia species, encoded tatA and tatC in different genome strands. The bracket indicates the organisms that share a common tat genes organization.