Database Accession: DI1100030
Name: Proteinase A complexed with IA3 peptide inhibitor
PDB ID: 1dpj
Experimental method: X-ray (1.80 Å)
Source organism: Saccharomyces cerevisiae
Proof of disorder:
Primary publication of the structure:
Li M, Phylip LH, Lees WE, Winther JR, Dunn BM, Wlodawer A, Kay J, Gustchina A
The aspartic proteinase from Saccharomyces cerevisiae folds its own inhibitor into a helix.
(2000) Nat. Struct. Biol. 7: 113-7
PMID: 10655612
Abstract:
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.
Annotations from the GeneOntology database. Only terms that fit at least two of the interacting proteins are shown.Molecular function: not assigned
Biological process:
cellular protein catabolic process The chemical reactions and pathways resulting in the breakdown of a protein by individual cells.
Cellular component:
Structural annotations of the participating protein chains.Entry contents: 2 distinct polypeptide molecules
Chains: B, A
Notes: No modifications of the original PDB file.
Name: Protease A inhibitor 3
Source organism: Saccharomyces cerevisiae
Length: 29 residues
Sequence:Sequence according to PDB SEQRESTDQQKVSEIFQSSKEKLQGDAKVVSDAFK
UniProtKB AC: P01094 (positions: 3-31) Coverage: 42.6%
UniRef90 AC: UniRef90_P01094 (positions: 3-31)
Name: Saccharopepsin
Source organism: Saccharomyces cerevisiae
Length: 329 residues
Sequence:Sequence according to PDB SEQRESGGHDVPLTNYLNAQYYTDITLGTPPQNFKVILDTGSSNLWVPSNECGSLACFLHSKYDHEASSSYKANGTEFAIQYGTGSLEGYISQDTLSIGDLTIPKQDFAEATSEPGLTFAFGKFDGILGLGYDTISVDKVVPPFYNAIQQDLLDEKRFAFYLGDTSKDTENGGEATFGGIDESKFKGDITWLPVRRKAYWEVKFEGIGLGDEYAELESHGAAIDTGTSLITLPSGLAEMINAEIGAKKGWTGQYTLDCNTRDNLPDLIFNFNGYNFTIGPYDYTLEVSGSCISAITPMDFPEPVGPLAIVGDAFLRKYYSIYDLGNNAVGLAKAI
UniProtKB AC: P07267 (positions: 77-405) Coverage: 81.2%
UniRef90 AC: UniRef90_P07267 (positions: 77-405)
Evidence demonstrating that the participating proteins are unstructured prior to the interaction and their folding is coupled to binding. Chain B:
The 1-68 region described in DisProt entry DP00179 cover 100% of the sequence present in the structure.
Chain A:
The aspartyl protease domain involved in the interaction is known to adopt a stable structure in isolation (see Pfam domain PF00026). A solved monomeric structure of the domain is represented by PDB ID 2jxr.
Structures from the PDB that contain the same number of proteins, and the proteins from the two structures show a sufficient degree of pairwise similarity, i.e. they belong to the same UniRef90 cluster (the full proteins exhibit at least 90% sequence identity) and convey roughly the same region to their respective interactions (the two regions from the two proteins share a minimum of 70% overlap). The structure can be rotated by left click and hold anywhere on the structure. Representation options can be edited by right clicking on the structure window.
