TABLE 3.

Decreased susceptibility of S. cerevisiae to BAY 10-8888 by overexpression of isoleucyl-tRNA synthetase^a

Growth medium	Plasmid	IC90b (μg/ml)	Sp act (U/mg of protein [mean ± SD])
			Isoleucyl-tRNA synthetase	Lysyl-tRNA synthetase
YNG	pG-1	64	0.32 ± 0.09	0.76 ± 0.11
	pAL664	128	2.38 ± 0.52	0.71 ± 0.15
TRP	pG-1	32	0.35 ± 0.07	0.78 ± 0.08
	pAL664	128	2.90 ± 0.51	0.97 ± 0.15

^aLogarithmic-phase cells grown at 30°C in YNG medium supplemented with 75 μg of uridine per ml (YNG) or minimal dextrose medium lacking tryptophan (TRP) were incubated at a cell density of 10³/ml in the same medium at 37°C in the presence of BAY 10-8888. After 48 h the IC₉₀ was determined. The specific activities of isoleucyl- and lysyl-tRNA synthetase in crude extract (S100) are given. 

^bThe IC₉₀ was defined as the lowest concentration preventing visible growth.