1try
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STRUCTURE OF INHIBITED TRYPSIN FROM FUSARIUM OXYSPORUM AT 1.55 ANGSTROMS
OverviewOverview
The structure of trypsin from the fungus Fusarium oxysporum has been, refined at 1.55 A resolution by restrained least-squares minimization to, an R-factor of 14.4%. The data were recorded from a single-crystal on the, X31 beamline at EMBL, Hamburg, using a locally developed image-plate, scanner. The final model consists of 1557 protein atoms, 400 water, molecules, one molecule of isopropanol and one monoisopropyl phosphoryl, inhibitor group covalently bound to the catalytic Ser195. Comparison of, the structure with bovine trypsin reveals significant differences in the, active site and suggests a possible explanation for the difference in, substrate specificity between the two enzymes. In F. oxysporum trypsin the, specificity pocket is larger than in bovine trypsin. This explains the, preference of F. oxysporum trypsin for the bulkier arginine over lysine, and the reverse preference in bovine trypsin. The binding cavity on the, C-terminal side of the substrate is more restricted in F. oxysporum, trypsin than in mammalian and Streptomyces griseus trypsins, which, explains the relative inactivity of F. oxysporum trypsin towards, peptide-pNA substrate analogues as an unfavourable steric interaction, between the side of the binding cavity and the para-nitroanilino group of, peptide-pNA. The observed restriction of the binding cavity does not lead, to a reduced catalytic activity compared to other trypsins.
About this StructureAbout this Structure
1TRY is a Single protein structure of sequence from Fusarium oxysporum with ISP and IPA as ligands. Active as Trypsin, with EC number 3.4.21.4 Full crystallographic information is available from OCA.
ReferenceReference
Structure of inhibited trypsin from Fusarium oxysporum at 1.55 A., Rypniewski WR, Dambmann C, von der Osten C, Dauter M, Wilson KS, Acta Crystallogr D Biol Crystallogr. 1995 Jan 1;51(Pt 1):73-85. PMID:15299338
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