Figure 9-2: Features of antitermination sites in early operons of lambdoid phages. A. Comparison of nut regions (L and R) of l and H-19B with components elements identified below (52,120). The arrows indicate regions of hyphenated dyad symmetry that are sources of stem-loop structures. B. The PUT stem-loop structures of phage HK022 (6). C. The GNRA fold-like structure formed by l BOXB upon interaction with N, shown here for the NUTR-BOXB, is based on the structure determined for NUTL-BOXB (101,162). Bases, sugars, and phosphates are represented respectively by rectangles (with base indicated within), ovals, and squares. Dashed lines shows hydrogen bonds of Watson-Crick pairing and heavy dashed line shows sheared G(6)-A(10) base pair. Bases are numbered from 3 end of upstream stem to 5 end of downstream stem. The purine ring of adenine 7 stacks with the indole ring of Trp18 of N and adenine 9 is extruded from the structure. (for better image quality, click here for tif image, which may be quite large; may also require screen refreshing plus special software to view; or view larger tif in separate window)

Figure 9-1, Figure 9-2, Figure 9-3, Figure 9-4

return to Friedman and Court, Regulation of l Gene Expression by Transcription Termination and Antitermination