Nuclear magnetic resonance spectroscopy is used to visualize directly an ensemble of transient, non-specific 'encounter' complexes for the first binary complex in the bacterial phosphotransferase system (the N-terminal domain of enzyme I and the phosphocarrier protein HPr). An atomic probability distribution map suggests that long-range electrostatic interactions facilitate the formation of the final protein–protein complex by reducing the dimensionality of the search process.
- Chun Tang
- Junji Iwahara
- G. Marius Clore
