1TO1: Crystal Structure Of The Complex Of Subtilisin Bpn' With Chymotrypsin Inhibitor 2 Y61a Mutant

Citation:
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.
PDB ID: 1TO1Download
MMDB ID: 30328
PDB Deposition Date: 2004/6/11
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 1.68  Å
Source Organism:
Hordeum vulgare subsp. vulgare
Similar Structures:
Biological Unit for 1TO1: dimeric; determined by author and by software (PISA)
Molecular Components in 1TO1
Label Count Molecule
Proteins (2 molecules)
1
Subtilisin Bpn'
Molecule annotation
1
Chymotrypsin Inhibitor 2
Molecule annotation
Chemicals (8 molecules)
1
1
2
1
3
2
4
4
* Click molecule labels to explore molecular sequence information.

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