Table 1.

Effects of upstream sequences on lac core promoter activity

Strain	Promoter	Miller units†	Relative activity
RLG 4288	lac (−40 to +52)*	50	1
RLG 4208	4192-lac hybrid	5,390	108
RLG 4282	rrnB P1-lac hybrid	1,940	39

^*The sequence from position −59 to −38 in this construct is 5′-gac tgc agt ggt acc tag gag g-3′. 

^†Average activity (two experiments with less than 2% variability).