4wbc
From Proteopedia
2.13 A STRUCTURE OF A KUNITZ-TYPE WINGED BEAN CHYMOTRYPSIN INHIBITOR PROTEIN
Overview
The crystal structure of a Kunitz-type double-headed alpha--chymotrypsin inhibitor from winged bean seeds has been refined at 2.13 A resolution using data collected from cryo-cooled (90 K) crystals which belong to the hexagonal space group P6(1)22 with unit-cell parameters a = b = 60.84, c = 207.91 A. The volume of the unit cell is reduced by 5.3% on cooling. The refinement converged to an R value of 20.0% (R(free) = 25.8%) for 11100 unique reflections and the model shows good stereochemistry, with r.m.s. deviations from ideal values for bond lengths and bond angles of 0.011 A and 1.4 degrees, respectively. The structural architecture of the protein consists of 12 antiparallel beta-strands joined in the form of a characteristic beta-trefoil fold, with the two reactive-site regions, Asn38-Leu43 and Gln63-Phe68, situated on two external loops. Although the overall protein fold is the same as that of the room-temperature model, some conformational changes are observed in the loop regions and in the side chains of a few surface residues. A total of 176 ordered water molecules and five sulfate ions are included in the model.
About this Structure
4WBC is a Single protein structure of sequence from Psophocarpus tetragonolobus. This structure supersedes the now removed PDB entry 3wbc. Full crystallographic information is available from OCA.
Reference
Cryocrystallography of a Kunitz-type serine protease inhibitor: the 90 K structure of winged bean chymotrypsin inhibitor (WCI) at 2.13 A resolution., Ravichandran S, Sen U, Chakrabarti C, Dattagupta JK, Acta Crystallogr D Biol Crystallogr. 1999 Nov;55(Pt 11):1814-21. PMID:10531477 Page seeded by OCA on Sun May 4 22:31:12 2008
