Computational Modeling of Allosteric Regulation in the Hsp90 Chaperones: A Statistical Ensemble Analysis of Protein Structure Networks and Allosteric Communications
Figure 3
Nucleotide-Dependent Conformational Changes in the HtpG Chaperone.
Conformational changes in the ADP-bound HtpG (A,B) and ATP-bound HtpG complexes (C,D) show that HtpG can experience opening and closing motions that are nucleotide-specific. The normalized frequency of the average distance between the HtpG-NTDs is shown for ADP-HtpG as a green-colored histogram (A) and for ATP-HtpG as red-colored histogram (C). The first bar in both histograms is deliberately truncated to make the small fraction of the distribution corresponding to the NTDs separation visible. The average structure of ADP-HtpG is shown in green ribbons (B) and the average conformation of ATP-HtpG is shown in red ribbons (D). The ADP-bound HtpG structure revealed a partial coordinated separation of the NTDs and MDs. The ATP-bound HtpG complex remained in the closed conformation during simulations.