Figure 2.

Phylogenetic analysis of the PLL family. A. Phylogenetic tree of PLLs, PTEs, and close homologues. Members of PLL-B are colored in green while within the PLL-As, mesophilic and archaeal PLLs are respectively colored in red and orange. The clades of PHPs, PTEs and RTXs were collapsed for clarity. All the sequences used for this tree are listed in Additional file 1: Table S1. B. Sequence alignment of BdPTE from B. diminuta, SsoPox from S. solfataricus, SacPox from S. acidocaldarius and DrOPH from D. radiodurans. Conserved amino acid residues are highlighted in black and similar residues in grey. Conserved active site residues involved in metals coordination are highlighted by red stars. Secondary structures are represented according to SsoPox structure (with pink arrows depicting β-sheets and red cylinders depicting α-helixes).