Solution structure of the GTPase activating domain of alpha s.

We have used heteronuclear three-dimensional NMR spectroscopy to determine the solution structure of a 141 residue protein containing the GTPase activating domain from the alpha chain of the heterotrimeric G protein Gs. The domain contains six alpha-helices and is stable and structured in solution despite having been excised from the intact Gs protein. The N-terminal ten and C-terminal 11 residues of the protein are unstructured in solution while the core is well determined by the 2483 distance and torsion restraints derived from the NMR spectra.