title: Crystal structure of trypsin-turkey egg white inhibitor complex.
abstract: Crystal structure of the complex between porcine beta-trypsin and the second domain of the Kazal-type ovomucoid turkey egg white trypsin inhibitor (OMTKY2) has been determined at 1.9A resolution. A peptide fragment from the first domain has been crystallized with the complex. Restrained-refinement of the structure led to an R-factor of 0.19 for the 32206 reflections. OMTKY2 exhibits the canonical Kazal-type fold with a central alpha-helix and a short two-stranded anti-parallel beta-sheet. The carbonyl carbon of the reactive site prefers trigonal geometry. The reactive site loop geometry of the inhibitor is complementary to the surface and charge of the binding site in beta-trypsin.
authors.affiliation: Department of crystallography and Biophysics, University of Madras, Chennai 600 025, India.
authors.forename: B Syed
authors.initials: BS
authors.lastname: Ibrahim
authors.forename: Vasantha
authors.initials: V
authors.lastname: Pattabhi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010059:Ovomucin / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D055672:Static Electricity; D013552:Swine; D014357:Trypsin / Q000737:chemistry* / Q000378:metabolism; D014361:Trypsin Inhibitors / Q000737:chemistry* / Q000378:metabolism; D014422:Turkeys; D014867:Water / Q000737:chemistry / Q000378:metabolism
chemical_list: D014361:Trypsin Inhibitors; D014867:Water; D010059:Ovomucin; D014357:Trypsin