  6.1.1.B3 | C101S/C103S |
site-directed mutagenesis, in the mutant the zinc ion still remains coordinated but the variant becomes structurally labile and acquires aggregation capacity. The extent of aggregation of the protein is significantly decreased in presence of the small substrates and more particularly by adenosine triphosphate. Addition of zinc increases significantly the solubility of the variant. The aminoacylation assay reveals a decrease in activity of the mutant even after addition of zinc as compared to the wild-type, although the secondary structure of the protein is not altered. Unlike wild type Glu-Q-RS, the mutant shows a strong tendency to aggregate in solution at room temperature, addition of a saturating concentration of the small substrate ATP and/or L-Glu decreases the rate of aggregation of C101S/C103S Glu-Q-RS, ATP has the most efficient effect |
746385 |
