Figure 1.

The starting coordinates used in the rigid body minimization calculations. In the initial coordinate frame, the x-ray structures of EIN (α and α/β domains comprising residues 2–230, shown in red and green, respectively) and HPr (blue) are separated by ≈38 Å and their relative orientation is completely different from that in the EIN–HPr complex. The C^α–C^α distance between the active site histidines (shown in yellow) is ≈92 Å.