Download MendeleyCrystal structure of Saccharomyces cerevisiae cytosolic aspartate aminotransferase.
Jeffery, C.J., Barry, T., Doonan, S., Petsko, G.A., Ringe, D.(1998) Protein Sci 7: 1380-1387
- PubMed: 9655342
- DOI: https://doi.org/10.1002/pro.5560070614
- Primary Citation of Related Structures:
1YAA - PubMed 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.
Organizational Affiliation:
Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts 02254-9110, USA.
