Fig. 1

Domain architecture of separases from representative metazoan genomes and universally conserved positions in the separase regulatory domain. (a) The α-solenoid regulatory domain is depicted in gray and C-terminal protease domain is shown in light orange. The N-terminal α-helical domain missing from nematode sequences, but conserved in separases from most metazoans, plants, and fungi (except for Saccharomycetes), is shown in green. D. melanogaster THR protein is shown in black. (b) Universally conserved N-terminal residues are shown on the C. elegans separase Cryo-EM structure (PDB 5MZ6). The two visible conserved residues that make up the cysteine motif (C450 and C453) are shown in red and are found as part of a solvent exposed loop between helices 15 and 16, while neither C448 nor H442 were resolved in the crystal structure. Another universally conserved residue, W93, is shown in blue