Figure 2.
Fig. 2. The refined model superimposed on a 2Fo-Fc
electron density map of the TAR RNA Ca1-binding site contoured
at 1.3 . Ca1
(yellow sphere) stabilizes the bulge backbone structure through
direct ligands with the phosphate oxygens of U23, C24, and G26.
Three water molecules, depicted as cyan-colored spheres,
complete the octahedral coordination. All Ca^2+-phosphate oxygen
distances are 2.3 Å. All Ca^2+-water distances are 2.4 Å.
. Ca1
(yellow sphere) stabilizes the bulge backbone structure through
direct ligands with the phosphate oxygens of U23, C24, and G26.
Three water molecules, depicted as cyan-colored spheres,
complete the octahedral coordination. All Ca^2+-phosphate oxygen
distances are 2.3 Å. All Ca^2+-water distances are 2.4 Å.