1TO2

crystal structure of the complex of subtilisin BPN' with chymotrypsin inhibitor 2 M59K, in pH 9 cryosoak

Summary for 1TO2

• Entry DOI: 10.2210/pdb1to2/pdb
• Related: 1tm1 1tm3 1tm4 1tm5 1tm7 1tmg 1to1
• Descriptor: Subtilisin BPN', chymotrypsin inhibitor 2, CALCIUM ION, ... (7 entities in total)
• Functional Keywords: serine protease, inhibitor, hydrolase
• Biological source: Bacillus amyloliquefaciens; More
• Cellular location: Secreted: P00782
• Total number of polymer chains: 2
• Total formula weight: 40699.78

Authors

Radisky, E.S.,Kwan, G.,Karen Lu, C.J.,Koshland Jr., D.E. (deposition date: 2004-06-11, release date: 2004-11-09, Last modification date: 2023-08-23)

Primary citation

Radisky, E.S.,Kwan, G.,Karen Lu, C.J.,Koshland Jr., D.E.
Binding, Proteolytic, and Crystallographic Analyses of Mutations at the Protease-Inhibitor Interface of the Subtilisin BPN'/Chymotrypsin Inhibitor 2 Complex(,).
Biochemistry, 43:13648-13656, 2004

PubMed Abstract: A series of mutants of chymotrypsin inhibitor 2 (CI2), at residues that interact with the inhibited enzyme subtilisin BPN', were studied to determine the relative importance of intermolecular contacts on either side of the scissile bond. Mutants were tested for inhibition of subtilisin, rates of hydrolysis by subtilisin, and ability to acylate subtilisin. Additionally, crystal structures of the mutant CI2 complexes with subtilisin were obtained. Ordered water molecules were found to play an important role in inhibitor recognition, and features of the crystal structures, in combination with biochemical data, support a transition-state stabilization role for the P(1) residue in subtilisin catalysis. Consistent with the proposed mechanism of inhibition, in which rapid acylation is followed by religation, leaving-group contacts with the enzyme were found to be more critical determinants of inhibition than acylating-group contacts in the mutants studied here.

PubMed: 15504027
DOI: 10.1021/bi048797k

Experimental method

X-RAY DIFFRACTION (1.3 Å)