|
Figure 4.
Figure 4. Cks1 anion-binding site and glutamine tail. (a)
Glu106 and Tyr107 residues (magenta bonds and polar atoms
colored spheres) within the C-terminal helix a3 (not present in
other Cks structures) bind to the five invariant residues
(Arg33, Arg42, Arg102, Ser82 and Trp85, orange bonds) forming
the anion-binding site located at the dimer interface of two
b-interchanged Cks1 dimers (yellow and blue subunits). In
addition, Arg111 in helix a3 stacks against Tyr30 in b1 (green
bonds in this interdimer interface). (b) Electron-density map
and model for the ordered position of the glutamine tail. Stereo
pair of the 3 Å resolution 2F[o]-F[c] electron-density maps,
contoured at 1.2s, showing the first four glutamine residues,
Gln118-Gln121, out of the 16 present in the Cks1 glutamine tail.
|
