Figure 2.

Topology diagram of the NlpC/P60 and structurally related proteases. The topology of the papain-like proteases (PDB:1ppn) and transglutaminases (PDB:1fie) are derived from the available crystal structures of these proteins. The predicted topology of the NlpC/P60 family members was derived from secondary structure and sequence conservation profile. Yellow arrows represent β strands and green cylinders represent α helices.

Anantharaman and Aravind Genome Biology 2003 4:R11   doi:10.1186/gb-2003-4-2-r11