Analyses of A. tamarense histone H2A.X. A) Alignment of A. tamarense H2A.X with eukaryotic homologs. The alignment is shaded according to the level of conservation. The symbols above the alignment indicate the location of functional residues (T = trypsin cleavage site, ^ = arginines that contact the DNA helix, * = H2A-H2B interaction sites, U = ubiquitination site). The annotation below the alignment indicates conserved structural features including the α-helices, loops, and the SQ(E/D)Φgotif. B) A ML tree of H2A and H2A.X. The numbers above and below the branches are the results of ML and NJ bootstrap analyses, respectively. The thick branches indicate > 0.95 posterior probability from Bayesian inference. Only bootstrap values ≥ 50% are shown. Branch lengths are proportional to the number of substitutions per site (see scale bar).