TABLE 1.

Interaction of mutant ɛ subunits with Pol III core subunits α and θ as determined in the yeast two-hybrid assay^a

dnaQ allele or deletion	β-Gal activityb for the following interaction:
	α-ɛ	θ-ɛ
Vectors only	0.001 ± 0.001	0.001 ± 0.001
dnaQ+	0.052 ± 0.032	37 ± 9
mutD5	0.030 ± 0.009	46 ± 18
dnaQ49	0.001 ± 0.001	0.015 ± 0.005
dnaQ991	0.001 ± 0.001	48 ± 5
NΔ186	0.098 ± 0.047	0.001 ± 0.001

^aYeast transformants carrying pGBT9-2-dnaQ and either pGAD424-holE or pGAD424-dnaE were grown as described by Jonczyk et al. (8). β-Galactosidase (β-Gal) assays were performed with extracts at 30°C according to the method of Rose et al. (19), including correction for spontaneous o-nitrophenyl-β-d-galactopyranoside (ONPG) hydrolysis under the given experimental conditions. Each value represents the average (± standard deviation) for three independent transformants, each analyzed in triplicate. Similar results were obtained in several repeated experiments. 

^bExpressed in units (amount of ONPG hydrolyzed per minute), calculated as (1,000 × OD₄₂₀)/(OD₆₀₀ × volume assayed × time), where OD₄₂₀ and OD₆₀₀ are the optical densities at 420 and 600 nm, respectively, volume is measured in milliliters, and time is measured in minutes.