1jrr

From Proteopedia

Revision as of 10:07, 20 March 2008

HUMAN PLASMINOGEN ACTIVATOR INHIBITOR-2.[LOOP (66-98) DELETIONMUTANT] COMPLEXED WITH PEPTIDE MIMIckING THE REACTIVE CENTER LOOP

Overview

The structure of the serpin, plasminogen activator inhibitor type-2 (PAI-2), in a complex with a peptide mimicking its reactive center loop (RCL) has been determined at 1.6-A resolution. The structure shows the relaxed state serpin structure with a prominent six-stranded beta-sheet. Clear electron density is seen for all residues in the peptide. The P1 residue of the peptide binds to a well defined pocket at the base of PAI-2 that may be important in determining the specificity of protease inhibition. The stressed-to-relaxed state (S --> R) transition in PAI-2 can be modeled as the relative motion between a quasirigid core domain and a smaller segment comprising helix hF and beta-strands s1A, s2A, and s3A. A comparison of the Ramachandran plots of the stressed and relaxed state PAI-2 structures reveals the location of several hinge regions connecting these two domains. The hinge regions cluster in three locations on the structure, ensuring a cooperative S --> R transition. We hypothesize that the hinge formed by the conserved Gly(206) on beta-strand s3A in the breach region of PAI-2 effects the S --> R transition by altering its backbone torsion angles. This torsional change is due to the binding of the P14 threonine of the RCL to the open breach region of PAI-2.

About this Structure

1JRR is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.

Reference

Crystal structure of the complex of plasminogen activator inhibitor 2 with a peptide mimicking the reactive center loop., Jankova L, Harrop SJ, Saunders DN, Andrews JL, Bertram KC, Gould AR, Baker MS, Curmi PM, J Biol Chem. 2001 Nov 16;276(46):43374-82. Epub 2001 Aug 23. PMID:11546761

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