Figure 2

Comparison of E. coli host, T4 early, and T4 middle promoter sequences. Top, Sequences and positions of host promoter recognition elements for σ⁷⁰-RNAP (UP, -35, TGn, -10) are shown [20, 150]. Below, similar consensus sequences found in T4 early [4] and middle [91] promoters are in black and differences are in red; the MotA box consensus sequence in T4 middle promoters is in green. Spacer lengths between the TGn elements and the -35 elements (host and T4 early) or the MotA box are indicated. W = A or T; R = A or G; Y = C or T, n = any nucleotide; an uppercase letter represents a more highly conserved base.