|
type |
Journal Article |
authors |
Jeffery, C. J.; Barry, T.; Doonan, S.; Petsko, G. A.; Ringe, D. |
title |
Crystal structure of Saccharomyces cerevisiae cytosolic aspartate aminotransferase |
journal |
Protein Sci |
Activity |
2.6.1.1 |
Family |
2.6.1.1.a |
sel |
selected |
ui |
9655342 |
year |
(1998) |
volume |
7 |
number |
6 |
pages |
1380-7 |
| |
keywords |
Animal |
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. |
last changed |
2010/11/09 16:02 |
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