Species signature of ArgC from Rhizobiales. A multiple alignment was carried out using CLUSTAL W. Species signatures were determined with a perl custom script. Yellow blocks indicate identical residues in at least two species. Colored residues for each organism denote species signature as follows: orange, R. etli; red, A. tumefaciens; blue, S. meliloti; gray, B. melitensis; and green, M. loti. Residues not in blocks are gaps in some organism or nonhomologous sequences.