Raptor protein contains a caspase-like domain

Using state-of-the-art sequence analysis and structure-prediction methods a caspase-like domain in the N-terminal region of raptor proteins has been identified. This domain, which is characterized by the presence of invariant catalytic Cys-His dyad, is evolutionarily and structurally related to known caspases and might have protease activity. This finding suggests several unexpected aspects of raptor function in the target of rapamycin (TOR) signaling pathway.