Refined crystal structure of the molecular complex of Streptomyces griseus protease B, a serine protease, with the third domain of the ovomucoid inhibitor from turkey.
We have determined the crystal structure of the molecular complex between Streptomyces griseus protease B (SGPB), a bacterial serine protease, and the third domain of the ovomucoid inhibitor from turkey. Restrained-parameter least-squares refinement of the structure with the 1.8-A intensity data set has resulted in an R factor of 0.125. The carbonyl carbon atom of the reactive bond between Leu-18 and Glu-19 in the inhibitor lies at a distance of 2.71 A from the O gamma atom of the nucleophilic Ser-195 in SGPB; this distance is 0.5 A shorter than a normal van der Waals contact. Unlike the reactive bond in the pancreatic trypsin inhibitor complexed with bovine trypsin, the Leu--Glu bond of the ovomucoid inhibitor is not distorted from planarity towards a pyramidal configuration.
D000818:Animals; D001665:Binding Sites; D003460:Crystallization; D004527:Egg Proteins; D010450:Endopeptidases; D010059:Ovomucin; D011485:Protein Binding; D011487:Protein Conformation; D012697:Serine Endopeptidases; D014422:Turkeys; D014961:X-Ray Diffraction
D004527:Egg Proteins; D010059:Ovomucin; D010450:Endopeptidases; D012697:Serine Endopeptidases; C024984:streptogrisin B