TABLE 2.

Analysis of prgI and prgJ translation^a

Strain genotype	LacZ activity (Miller units)
	prgI-lacZ	prgJ-lacZ
Wild type	5,355 ± 335	490 ± 16
ΔinvA	5,412 ± 145	565 ± 15
ΔinvJ	5,901 ± 214	468 ± 31
ΔprgI	6,067 ± 325	511 ± 17
ΔprgJ	5,474 ± 162	467 ± 7

^aprgI and prgJ translational fusions to lacZ were constructed as follows by using the translational fusion vector plasmid pRS414 (10). DNA fragments containing prgI or prgJ were amplified by PCR and inserted into the EcoRI and BamHI sites of pRS414 so as to create in-frame fusions to lacZ. In either case, the 5′ primer started 370 bp upstream of the prgH gene and therefore contained the native promoter that drives the expression of prgI and prgJ (6). The resulting fusions contained 50 and 60 amino acids of PrgI and PrgJ, respectively, fused to LacZ. The levels of translation of the prgI and prgJ reporter gene fusions in the different strains were monitored by assaying the levels of β-galactosidase activity. Cells were grown under inducing conditions to an OD₆₀₀ of 0.8, and β-galactosidase activity was assayed as described previously (9). Values are means and standard deviations of one experiment performed with triplicate samples. Equivalent results were obtained in several repetitions of this experiment.