PMID:8125098
| Citation |
Altamirano, MM, Hernandez-Arana, A, Tello-Solis, S and Calcagno, ML (1994) Spectrochemical evidence for the presence of a tyrosine residue in the allosteric site of glucosamine-6-phosphate deaminase from Escherichia coli. Eur. J. Biochem. 220:409-13 |
|---|---|
| Abstract |
The interaction of the enzyme glucosamine 6-phosphate deaminase from Escherichia coli with its allosteric activator, N-acetyl-D-glucosamine 6-phosphate, was studied by different spectrophotometric methods. Analysis of the circular-dichroism differential spectra produced by the binding of the allosteric activator or the competitive inhibitor 2-amino-2-deoxy-D-glucitol 6-phosphate (a homotropic ligand displacing the allosteric equilibrium to the R conformer), strongly suggests the presence of tyrosine residues at or near the allosteric site, although a conformational effect cannot be ruled out. The involvement of a single tyrosine residue in the N-acetyl-D-glucosamine-6-phosphate binding site of glucosamine-6-phosphate deaminase was supported by spectrophotometric pH titrations performed in the presence or absence of the homotropic and heterotropic ligand. In these experiments, a single titrated tyrosine residue is completely protected by saturation with the allosteric activator; this group is considerably acidic (pK 8.75). The analysis of the amino acid sequence of the deaminase using a set of indices for the prediction of surface accessibility of amino acid residues, suggests that the involved residue may be Tyr121 or Tyr254. |
| Links | |
| Keywords |
Aldose-Ketose Isomerases; Allosteric Site; Amino Acid Sequence; Carbohydrate Epimerases/chemistry; Carbohydrate Epimerases/isolation & purification; Circular Dichroism; Escherichia coli/enzymology; Hydrogen-Ion Concentration; Molecular Sequence Data; Protein Conformation; Spectrophotometry, Ultraviolet; Tyrosine |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
References
See Help:References for how to manage references in EcoliWiki.