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spinqualitylabelsall models 1yeg, resolution 2.0Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

STRUCTURE OF IGG2A FAB FRAGMENT (D2.3) COMPLEXED WITH REACTION PRODUCT

Overview

The x-ray structures of the unliganded esterase-like catalytic antibody, D2.3 and its complexes with a substrate analogue and with one of the, reaction products are analyzed. Together with the structure of the, phosphonate transition state analogue hapten complex, these crystal, structures provide a complete description of the reaction pathway. At, alkaline pH, D2.3 acts by preferential stabilization of the negatively, charged oxyanion intermediate of the reaction that results from hydroxide, attack on the substrate. A tyrosine residue plays a crucial role in, catalysis: it activates the ester substrate and, together with an, asparagine, it stabilizes the oxyanion intermediate. A canal allows facile, diffusion of water molecules to the reaction center that is deeply buried, in the structure. Residues bordering this canal provide targets for, mutagenesis to introduce a general base in the vicinity of the reaction, center.

About this Structure

1YEG is a Protein complex structure of sequences from Mus musculus with ACT, ZN and BPN as ligands. Full crystallographic information is available from OCA.

Reference

X-ray structures of a hydrolytic antibody and of complexes elucidate catalytic pathway from substrate binding and transition state stabilization through water attack and product release., Gigant B, Charbonnier JB, Eshhar Z, Green BS, Knossow M, Proc Natl Acad Sci U S A. 1997 Jul 22;94(15):7857-61. PMID:9223277

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