1pek
From Proteopedia
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STRUCTURE OF THE COMPLEX OF PROTEINASE K WITH A SUBSTRATE-ANALOGUE HEXA-PEPTIDE INHIBITOR AT 2.2 ANGSTROMS RESOLUTION
Overview
The crystal structure of a transition state/product complex formed by the interaction between proteinase K and the substrate analogue N-Ac-L-Pro-L-Ala-L-Pro-L-Phe-D-Ala-L-Ala-NH2 has been determined at a resolution of 2.2 A and refined to an R-factor of 0.165 for 12,725 reflections. The inhibitor forms a stable complex through a series of hydrogen bonds with protein atoms and water molecules. The inhibitor is hydrolyzed between Phe 4I and D-Ala5I (I indicates inhibitor). The two fragments are separated by a distance of 3.07 A between the carbonyl carbon and the main chain nitrogen. Both fragments remain bound to the protein. The N-terminal fragment occupies subsites S5 to S1, whereas the C-terminal part is bound in S1' and S2', the first time that electron density for a substrate analogue has been observed in the P1' and P2' sites of a subtilisin-like enzyme. The flexible segments of the substrate recognition sites Gly100-Tyr104 and Ser132-Gly136 move appreciably to accommodate the inhibitor. Biochemical results indicate an inhibition by this specifically designed peptide of 95%.
About this Structure
1PEK is a Single protein structure of sequence from [1]. Active as Peptidase K, with EC number 3.4.21.64 Full crystallographic information is available from OCA.
Reference
Structure of the complex of proteinase K with a substrate analogue hexapeptide inhibitor at 2.2-A resolution., Betzel C, Singh TP, Visanji M, Peters K, Fittkau S, Saenger W, Wilson KS, J Biol Chem. 1993 Jul 25;268(21):15854-8. PMID:8340410
Page seeded by OCA on Thu Feb 21 14:28:02 2008
