Analysis of dinoflagellate HLPs. A) HLPs from dinoflagellates (red taxa names) and bacteria (blue) and HU proteins from bacteria (black). B) The predicted secondary structure of HLPs from A. tamarense and B. pertussis aligned with the known secondary structure of E. coli HU. Curled lines indicate α-helices and jagged lines indicate β-strands. The arrow indicates the position of a conserved lysine. The asterisk indicates the proline that intercalates into the DNA in HU proteins. C) An ML tree of HU and HLP proteins from bacteria and eukaryotes. The numbers above and below the branches result from 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).