Fig. 1.

Bacteriophage T4 and its long tail fibers. (A and B) Schematic representations of bacteriophage T4 attached to a bacterial membrane before (Left) and after (Right) contraction of the outer tail tube. The tip domain of gp37 is boxed. (C) Schematic representation of the bacteriophage T4 long tail fiber. Domains P1–5 correspond to gp34; the kneecap domain (K-C) is formed by gp35, whereas the distal part of the fiber, consisting of gp36 and gp37, is divided into regions D1–11. The expressed protein, gp37(651–1026), corresponds to D9-11 (larger gray box), whereas the crystallized fragment, gp37(785–1026), corresponds to D10–11 (smaller gray box).