2cjy: Difference between revisions

Caspases are cysteine proteases involved in the signalling cascades of, programmed cell death in which caspase-3 plays a central role, since it, propagates death signals from intrinsic and extrinsic stimuli to, downstream targets. The atomic resolution (1.06 Angstroms) crystal, structure of the caspase-3 DEVD-cmk complex reveals the structural basis, for substrate selectivity in the S4 pocket. A low-barrier hydrogen bond is, observed between the side-chains of the P4 inhibitor aspartic acid and, Asp179 of the N-terminal tail of the symmetry related p12 subunit., Site-directed mutagenesis of Asp179 confirmed the significance of this, residue in substrate recognition. In the 1.06 Angstroms crystal structure, a radiation damage induced rearrangement of the inhibitor methylketone, moiety was observed. The carbon atom that in a substrate would represent, the scissile peptide bond carbonyl carbon clearly shows a tetrahedral, coordination and resembles the postulated tetrahedral intermediate of the, acylation reaction.

2CJY is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with PHQ as [http://en.wikipedia.org/wiki/ligand ligand]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2CJY OCA].  

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