Table 2. Upstream primers used to construct rrnB P1 promoters with displaced consensus UP elements.

^aThe 5′ end of each primer has the sequence 5′-GCGCGAATTCGGAAAATTTTTTTTAAAAAAGA-3′, denoted by an ‘X’ in the table, containing an EcoRI site (underlined) and a consensus UP element (emboldened). The rrnB P1 –35 region and SUB sequences are underlined and emboldened, respectively, in the table. rrnB P1 derivatives in which the consensus UP element has been displaced by 5–22 bp contain part or all of the SUB sequence (17) whereas derivatives in which this element has been displaced by 27 and 33 bp contain, in addition, sequences from –37 to –47 of the lac P1 promoter (italicised and emboldened), which do not possess inherent UP element-like activity (13). Zero base pair displacement corresponds to the wild type location for the UP element, i.e. positions –38 to –59.