Structural and Functional Analyses of PAS Domain Interactions of the Clock Proteins Drosophila PERIOD and Mouse PERIOD2 (original) (raw)
Figure 4
Structural Analysis of PAS Domain Interactions in mPER2[170–473]
(A) Ribbon presentation of the mPER2[170–473] homodimer with molecule 1 shown in dark blue, molecule 2 in grey. The conserved Trp419 residues are shown as atomic stick figure.
(B) Close-up view of the dimer interface formed by antiparallel packing of the PAS-B β-sheet surfaces. Interacting residues are highlighted as atomic stick figure. Residues Trp419, Ile427, and Phe415 have been mutated within this study. Top, molecule 1 in dark blue; bottom, molecule 2 in grey.
(C) Close-up view of the dimer interface formed by antiparallel packing of the PAS-B β-sheet surfaces. Residues and water molecules mediating dimer interactions are highlighted as atomic stick figures and red spheres. Pro390, Phe425, and Glu342 have been omitted for clarity. Ser414 and Ile416 establish main chain interactions to water molecules in the interface. The 1 sigma 2fo-fc composite omit map is shown in blue. Similar view as in Figure 4B, but with molecules 1 and 2 switched/rotated around the noncrystallographic symmetry (NCS) axis. Top, molecule 2 in dark blue; bottom, molecule 1 in grey.
(D) Close-up view showing dimer interactions of the PAS-A domain with the PAS-B domain and helix αE. Interacting residues are highlighted as atomic stick figure. Pairs of interacting residues (hydrogen bond or van der Waals interactions) are connected by dashed lines.