Quaternary structure built from subunits combining NMR and small-angle x-ray scattering data.
A new principle in constructing molecular complexes from the known high-resolution domain structures joining data from NMR and small-angle x-ray scattering (SAXS) measurements is described. Structure of calmodulin in complex with trifluoperazine was built from N- and C-terminal domains oriented based on residual dipolar couplings measured by NMR in a dilute liquid crystal, and the overall shape of the complex was derived from SAXS data. The residual dipolar coupling data serves to reduce angular degrees of freedom, and the small-angle scattering data serves to confine the translational degrees of freedom. The complex built by this method was found to be consistent with the known crystal structure. The study demonstrates how approximate tertiary structures of modular proteins or quaternary structures composed of subunits can be assembled from high-resolution structures of domains or subunits using mutually complementary NMR and SAXS data.
VTT Biotechnology, FIN-02044 VTT, Espoo, Finland.
Maija-Liisa
ML
Mattinen
Kimmo
K
Pääkkönen
Teemu
T
Ikonen
Jeremy
J
Craven
Torbjörn
T
Drakenberg
Ritva
R
Serimaa
Jonathan
J
Waltho
Arto
A
Annila
D002147:Calmodulin / Q000737:chemistry / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015233:Models, Statistical; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D012542:Scattering, Radiation; D014268:Trifluoperazine / Q000494:pharmacology; D014961:X-Ray Diffraction; D014965:X-Rays
D002147:Calmodulin; D014268:Trifluoperazine