Crystal structure of Saccharomyces cerevisiae cytosolic aspartate aminotransferase.
Protein Sci
; 7(6): 1380-7, 1998 Jun.
Article
en En
| MEDLINE
| ID: mdl-9655342
ABSTRACT
The crystal structure of Saccharomyces cerevisiae cytoplasmic aspartate aminotransferase (EC 2.6.1.1) has been determined to 2.05 A resolution in the presence of the cofactor pyridoxal-5'-phosphate and the competitive inhibitor maleate. The structure was solved by the method of molecular replacement. The final value of the crystallographic R-factor after refinement was 23.1% with good geometry of the final model. The yeast cytoplasmic enzyme is a homodimer with two identical active sites containing residues from each subunit. It is found in the "closed" conformation with a bound maleate inhibitor in each active site. It shares the same three-dimensional fold and active site residues as the aspartate aminotransferases from Escherichia coli, chicken cytoplasm, and chicken mitochondria, although it shares less than 50% sequence identity with any of them. The availability of four similar enzyme structures from distant regions of the evolutionary tree provides a measure of tolerated changes that can arise during millions of years of evolution.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Aspartato Aminotransferasas
/
Saccharomyces cerevisiae
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Año:
1998
Tipo del documento:
Article