TABLE 2.

Luciferase activity in R. rubrum cultures carrying plasmids with inserts upstream of luc^a

Plasmid	Features upstream of luc	Activity of strain in medium
		S1MJ		UR381
		N−	N+	N−	N+
pSNCBP1	glnBp1	769	509	947	741
pSNCB1	glnBp1 and glnBp2	21,007	1,231	2,291	1,950
pSNCB1A	glnBp1, glnBp2, and glnB	9,302	1,508	2,543	2,170
pSNCB2	glnBp2	4,070	1,042	1,418	1,140
pSNCB2A	glnBp2 and glnB	3,494	1,169	1,662	1,302
pSNCA1+	glnB	194	168	171	159
pSNCA1−	glnB, reversed direction	150	138	140	110
pSNCglnA	3′ of Bg in glnB	165	141	150	135
pSNCref	53 bp upstream of glnA	179	163	123	110
pSNC109	No promoter	140	128	127	125
pSNC208	No promoter	135	141	124	131

^aR. rubrum S1MJ and UR381 (ntrBC⁻) were anaerobically grown in NH₄⁴-containing (N+) or N-free (N−) medium. Luciferase activity was measured in the cell extract as quanta seconds⁻¹ nanograms of protein⁻¹. The data shown are the averages of three independent assays. The standard deviation was less than 15% of the average.