2cjy

From Proteopedia

Revision as of 16:06, 5 November 2007

EXTENDED SUBSTRATE RECOGNITION IN CASPASE-3 REVEALED BY HIGH RESOLUTION X-RAY STRUCTURE ANALYSIS

Overview

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.

About this Structure

2CJY is a Protein complex structure of sequences from Homo sapiens with PHQ as ligand. Structure known Active Site: AC1. Full crystallographic information is available from OCA.

Reference

Extended substrate recognition in caspase-3 revealed by high resolution X-ray structure analysis., Ganesan R, Mittl PR, Jelakovic S, Grutter MG, J Mol Biol. 2006 Jun 23;359(5):1378-88. Epub 2006 May 11. PMID:16787777

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