Figure 2.

H-bonding between Asp¹⁰⁹ and His²². Distances between the two terminal oxygen atoms (O^α and O^β) of the Asp¹⁰⁹ residue and the hydrogen at the N^ɛ of His²¹ were measured during the second half of MD simulations (ns 5–10) for the EF-Tu•GDP and EF-Tu•GTP complexes and plotted as bars. Distances are shown for the O^α and O^β oxygen atoms of the aspartate side chain in the GDP (A) and GTP (B) complexes. The superimposed Gaussian fits indicate the contribution of the H-bonded (gray) and non-bonded (black) states.