FIGURE 3.

Surface electrostatic potentials of selected Hfq proteins. Views of the surface electrostatic potentials of the proximal faces of (A) Lm Hfq, (B) Sa Hfq (PDB: 1KQ1), (C) St Hfq (PDB:2YLB), and (D) Ec Hfq (PDB:1HK9), contoured at ±3 kT/e (T = 310 K). Calculations were made using the APBS plug-in in PyMol (Baker et al. 2001). N.B.: The pore of Lm Hfq, the U₆ RNA binding location, is less positive than the other three Hfq proteins. The electrostatic surface of the proximal pore of each protein likely has a strong influence on the binding affinity of each protein for U₆ RNA.