PDBsum entry 1ok0

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Inhibitor PDB id
Protein chain
74 a.a. *
GOL ×2
Waters ×159
* Residue conservation analysis
PDB id:
Name: Inhibitor
Title: Crystal structure of tendamistat
Structure: Alpha-amylase inhibitor hoe-467a. Chain: a. Synonym: tendamistat
Source: Streptomyces tendae. Organism_taxid: 1932. Strain: 4158. Atcc: 31210
0.93Å     R-factor:   0.102     R-free:   0.130
Authors: V.Koenig,L.Vertesy,T.R.Schneider
Key ref:
V.König et al. (2003). Structure of the alpha-amylase inhibitor tendamistat at 0.93 A. Acta Crystallogr D Biol Crystallogr, 59, 1737-1743. PubMed id: 14501112 DOI: 10.1107/S0907444903015828
16-Jul-03     Release date:   15-Jan-04    
Go to PROCHECK summary

Protein chain
Pfam   ArchSchema ?
P01092  (IAA_STRTE) -  Alpha-amylase inhibitor HOE-467A
104 a.a.
74 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 1 residue position (black cross)

 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     negative regulation of catalytic activity   1 term 
  Biochemical function     alpha-amylase inhibitor activity     1 term  


DOI no: 10.1107/S0907444903015828 Acta Crystallogr D Biol Crystallogr 59:1737-1743 (2003)
PubMed id: 14501112  
Structure of the alpha-amylase inhibitor tendamistat at 0.93 A.
V.König, L.Vértesy, T.R.Schneider.
The crystal structure of the proteinaceous alpha-amylase inhibitor tendamistat has been determined at 100 K to a resolution of 0.93 A. The final R factor for all reflections with F > 4sigma(F) is 9.26%. The mean coordinate error for fully occupied protein atoms as derived from full-matrix inversion is 0.018 A. An extended network of multiple discrete conformations has been identified on the side of tendamistat that binds to the target molecule. Most notably, residue Tyr15, which interacts with the glycine-rich loop characteristic of mammalian amylases, and a cluster of amino-acid side chains surrounding it are found in two well defined conformations. The flexibility observed in this crystal structure together with information about residues fixed by lattice contacts in the crystal but found to be mobile in a previous NMR study supports a model in which most of the residues involved in binding are not fixed in the free form of the inhibitor, suggesting an induced-fit type of binding.
  Selected figure(s)  
Figure 1.
Figure 1 Histogram of angles in the atomic resolution structure of tendamistat.
Figure 2.
Figure 2 2F[o] - F[c] electron-density map around residues Tyr20 and Ser21 contoured at 1.0 . The carboxyl group of Ser21 is left out for clarity. The figure was prepared with BOBSCRIPT (Kraulis, 1991[Kraulis, P. J. (1991). J. Appl. Cryst. 24, 946-950.]; Esnouf, 1999[Esnouf, R. M. (1999). Acta Cryst. D55, 938-940.]).
  The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (2003, 59, 1737-1743) copyright 2003.  
  Figures were selected by an automated process.