Fig. 3.

Human caspase organization. Caspases are grouped on the left according to function, either initiators or effectors of apoptosis, and on the right according to the recognition sequence of the substrate. One should note that the Group I, inflammatory, caspases (–1, –4, and –5) are not included in this figure. Each caspase has an N-terminal prodomain, where some contain either a CARD (caspase recruitment domain) or DED (death effector domain), followed by the large subunit (Large), an intersubunit linker, and the small subunit (Small). The numbers on each caspase molecule refer to the length of each specific domain, which was determined using the NCBI domain organization database (http://www.ncbi.nlm.nih.gov/).