Structures of Escherichia coli tryptophanase in holo and ‘semi-holo’ forms
| Autor: | Yehuda Goldgur, Leah Raznov, Rivka Cohen-Luria, Orna Almog, Garik Y. Gdalevsky, Abraham H. Parola, Anna Kogan |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Models
Molecular Stereochemistry Biophysics macromolecular substances medicine.disease_cause Crystallography X-Ray Biochemistry environment and public health Cofactor Protein Structure Secondary law.invention Research Communications chemistry.chemical_compound Apoenzymes Structural Biology law Catalytic Domain Genetics medicine Escherichia coli Crystallization Pyridoxal phosphate biology Chemistry Escherichia coli Proteins Tryptophanase Tryptophan Active site Condensed Matter Physics Lyase Crystallography Pyridoxal Phosphate biology.protein Protein Binding |
| Popis: | Two crystal forms ofEscherichia colitryptophanase (tryptophan indole-lyase, Trpase) were obtained under the same crystallization conditions. Both forms belonged to the same space groupP43212 but had slightly different unit-cell parameters. The holo crystal form, with pyridoxal phosphate (PLP) bound to Lys270 of both polypeptide chains in the asymmetric unit, diffracted to 2.9 Å resolution. The second crystal form diffracted to 3.2 Å resolution. Of the two subunits in the asymmetric unit, one was found in the holo form, while the other appeared to be in the apo form in a wide-open conformation with two sulfate ions bound in the vicinity of the active site. The conformation of all holo subunits is the same in both crystal forms. The structures suggest that Trpase is flexible in the apo form. Its conformation partially closes upon binding of PLP. The closed conformation might correspond to the enzyme in its active state with both cofactor and substrate bound in a similar way as in tyrosine phenol-lyase. |
| Databáze: | OpenAIRE |
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