TABLE 2.

Expression from PR3 at 37°C and 20°C

Strain	Mean β-Galactosidase activity (Miller units) ± SEMa
	37°C	20°C
P90C(pRS415)	132 ± 17	100 ± 7
P90C(pRSA)	1319 ± 90	120 ± 9
P90C(pRSB)	140 ± 15	158 ± 15
P90C(pRSC)	10,326 ± 252	12,000 ± 190

^aβ-Galactosidase activity of P90C bearing either the promoter probe plasmid pRS415 or derivatives was assayed at 37°C and 20°C. Plasmids pRSA, pRSB, and pRSC are described in Fig. 1 and Table 1. Data are the means of three independent experiments performed in triplicate.