title: X-ray crystallographic structure of a papain-leupeptin complex.
abstract: The three-dimensional structure of the papain-leupeptin complex has been determined by X-ray crystallography to a resolution of 2.1 A (overall R-factor = 19.8%). The structure indicates that: (i) leupeptin contacts the S subsites of the papain active site and not the S' subsites; (ii) the 'carbonyl' carbon atom of the inhibitor is covalently bound by the Cys-25 sulphur atom of papain and is tetrahedrally coordinated; (iii) the 'carbonyl' oxygen atom of the inhibitor faces the oxyanion hole and makes hydrogen bond contacts with Gln-19 and Cys-25.
authors.affiliation: University of Oxford, Laboratory of Molecular Biophysics, UK.
authors.forename: E
authors.initials: E
authors.lastname: Schröder
authors.forename: C
authors.initials: C
authors.lastname: Phillips
authors.forename: E
authors.initials: E
authors.lastname: Garman
authors.forename: K
authors.initials: K
authors.lastname: Harlos
authors.forename: C
authors.initials: C
authors.lastname: Crawford
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D003461:Crystallography; D066298:In Vitro Techniques; D007976:Leupeptins / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010206:Papain / Q000648:ultrastructure*; D017434:Protein Structure, Tertiary; D014961:X-Ray Diffraction
chemical_list: D007976:Leupeptins; D010206:Papain; C032854:leupeptin