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1dpj
From Proteopedia
THE STRUCTURE OF PROTEINASE A COMPLEXED WITH IA3 PEPTIDE INHIBITOR
Overview
Aspartic proteinase A from yeast is specifically and potently inhibited by a small protein called IA3 from Saccharomyces cerevisiae. Although this inhibitor consists of 68 residues, we show that the inhibitory activity resides within the N-terminal half of the molecule. Structures solved at 2.2 and 1.8 A, respectively, for complexes of proteinase A with full-length IA3 and with a truncated form consisting only of residues 2-34, reveal an unprecedented mode of inhibitor-enzyme interactions. Neither form of the free inhibitor has detectable intrinsic secondary structure in solution. However, upon contact with the enzyme, residues 2-32 become ordered and adopt a near-perfect alpha-helical conformation. Thus, the proteinase acts as a folding template, stabilizing the helical conformation in the inhibitor, which results in the potent and specific blockage of the proteolytic activity.
About this Structure
1DPJ is a Protein complex structure of sequences from Saccharomyces cerevisiae. Full crystallographic information is available from OCA.
Reference
The aspartic proteinase from Saccharomyces cerevisiae folds its own inhibitor into a helix., Li M, Phylip LH, Lees WE, Winther JR, Dunn BM, Wlodawer A, Kay J, Gustchina A, Nat Struct Biol. 2000 Feb;7(2):113-7. PMID:10655612 Page seeded by OCA on Fri May 2 14:07:16 2008
