2wbc
From Proteopedia
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REFINED CRYSTAL STRUCTURE (2.3 ANGSTROM) OF A WINGED BEAN CHYMOTRYPSIN INHIBITOR AND LOCATION OF ITS SECOND REACTIVE SITE
Overview
The crystal structure of a double-headed alpha-chymotrypsin inhibitor, WCI, from winged bean seeds has now been refined at 2.3 A resolution to an, R-factor of 18.7% for 9,897 reflections. The crystals belong to the, hexagonal space group P6(1)22 with cell parameters a = b = 61.8 A and c =, 212.8 A. The final model has a good stereochemistry and a root mean square, deviation of 0.011 A and 1.14 degrees from ideality for bond length and, bond angles, respectively. A total of 109 ordered solvent molecules were, localized in the structure. This improved structure at 2.3 A led to an, understanding of the mechanism of inhibition of the protein against, alpha-chymotrypsin. An analysis of this higher resolution structure also, helped us to predict the location of the second reactive site of the, protein, about which no previous biochemical information was available., The inhibitor structure is spherical and has twelve anti-parallel, beta-strands with connecting loops arranged in a characteristic, beta-trefoil fold common to other homologous serine protease inhibitors in, the Kunitz (STI) family as well as to some non homologous functionally, unrelated proteins. A wide variation in the surface loop regions is seen, in the latter ones.
About this Structure
2WBC is a Single protein structure of sequence from Psophocarpus tetragonolobus. Known structural/functional Sites: and . Full crystallographic information is available from OCA.
Reference
Refined crystal structure (2.3 A) of a double-headed winged bean alpha-chymotrypsin inhibitor and location of its second reactive site., Dattagupta JK, Podder A, Chakrabarti C, Sen U, Mukhopadhyay D, Dutta SK, Singh M, Proteins. 1999 May 15;35(3):321-31. PMID:10328267
Page seeded by OCA on Sun Feb 3 10:51:31 2008
