Fig. 2

Conservation of stabilizing “plug” motif in GDPD-like SMaseD/PLD. a Ribbon diagram showing C-terminal motif (orange) and interacting N-terminal residues (cyan). Most notable in the C-terminal motif are an Arg-Asp (RD) salt bridge (blue arrows), Ala and Pro residues that participate in hydrophobic interactions (green arrows), and a Trp side chain that packs into the bottom of the β-barrel (black arrow). b Sequence logos (weblogo.berkeley.edu) depicting residue conservation in the C-terminal motif (positions 7–17 of the logo) plus interacting N-terminal residues (1–3 and 5 of the logo). The actinobacterial-toxin like (AT-like) and sicariid-toxin like (ST-like) clades conserve a very similar motif, as do the basal, proteobacterial dominated sequences (other), while the version of the motif in the Aquatic clade is recognizable but somewhat divergent