FIGURE 2.

Solution structure of the tandem WW domains of HYPA as determined by NMR spectroscopy. A, backbone superposition of the 10 lowest-energy structures of 2WW is shown. B, shown is a ribbon representation of the structure of 2WW. C, a comparison of the three-dimensional structures of WW1 in the context of 2WW (cyan) and the isolated WW1 (PDB ID 1YWJ, purple) is shown. The backbone traces of the structures in two types of WW1 are superimposed. D, fluorescence titration for the binding of the 2WW mutants with different interdomain linkers with DNS-labeled PRR (Htt-PP35) is shown. black, P67T; red, GS-Sub; blue, Su(dx)-Linker. The sequences with different linkers are shown below the titration curves.