Figure 3.

Overexpression of A. thaliana MetRS in E. coli. Protein extracts of isopropyl β-d-thiogalactoside-induced E. coli cells containing pQE52 or pQE52–MetRS were analyzed on a 10% polyacrylamide gel in the presence of SDS (Right). Induction of a 62-kDa protein (arrowhead) was obtained in the bacteria containing pQE52–MetRS. MetRS activity in the protein extract from the pQE52–MetRS strain was measured by using 1 μg of mitochondrial (♦) or chloroplast (⋄) tRNAs as a substrate (Left) and was compared with the activity in the control protein extract from the pQE52 strain (▴) by using chloroplast tRNAs as a substrate.