1k86
From Proteopedia
Crystal structure of caspase-7
Overview
Apoptosis is primarily executed by active caspases, which are derived from the inactive procaspase zymogens through proteolytic cleavage. Here we report the crystal structures of a caspase zymogen, procaspase-7, and an active caspase-7 without any bound inhibitors. Compared to the inhibitor-bound caspase-7, procaspase-7 zymogen exhibits significant structural differences surrounding the catalytic cleft, which precludes the formation of a productive conformation. Proteolytic cleavage between the large and small subunits allows rearrangement of essential loops in the active site, priming active caspase-7 for inhibitor/substrate binding. Strikingly, binding by inhibitors causes a 180 degrees flipping of the N terminus in the small subunit, which interacts with and stabilizes the catalytic cleft. These analyses reveal the structural mechanisms of caspase activation and demonstrate that the inhibitor/substrate binding is a process of induced fit.
About this Structure
1K86 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Crystal structure of a procaspase-7 zymogen: mechanisms of activation and substrate binding., Chai J, Wu Q, Shiozaki E, Srinivasula SM, Alnemri ES, Shi Y, Cell. 2001 Nov 2;107(3):399-407. PMID:11701129 Page seeded by OCA on Fri May 2 22:25:10 2008
Categories: Homo sapiens | Single protein | Alnemri, E S. | Chai, J. | Shi, Y. | Shiozaki, E. | Srinivasa, S M. | Wu, Q. | Activation | Apoptosis | Caspase | Zymogen
