Table 1.

MsrA activity in yeast cells

Enzyme	Specific activity (pmol/min/mg protein) on substrate
	Dabsyl-MetO	L-(3H) MetO
Extract of yeast parental WT strain	68	15
Extract of yeast NM strain	0	5
Extract of yeast OP strain	1700	300
Extract of yeast NM strain + YEp351 harboring the msrA gene with a frameshift mutation	0	5

Yeast extracts from the different strains were prepared by breaking the cells in 25 mM Tris⋅HCl (pH 7.5) in a French pressure cell. The MsrA activity was determined as described in Materials and Methods. WT, wild-type + YEp351; NM, msrA null mutant + YEp351; OP, overproducer strain (NM strain harboring YEp351 + msrA gene).