Lanthanide labeling offers fast NMR approach to 3D structure determinations of protein-protein complexes.
A novel nuclear magnetic resonance (NMR) strategy based on labeling with lanthanides achieves rapid determinations of accurate three-dimensional (3D) structures of protein-protein complexes. The method employs pseudocontact shifts (PCS) induced by a site-specifically bound lanthanide ion to anchor the coordinate system of the magnetic susceptibility tensor in the molecular frames of the two molecules. Simple superposition of the tensors detected in the two protein molecules brings them together in a 3D model of the protein-protein complex. The method is demonstrated with the 30 kDa complex between two subunits of Escherichia coli polymerase III, comprising the N-terminal domain of the exonuclease subunit epsilon and the subunit theta. The 3D structures of the individual molecules were docked based on a limited number of PCS observed in 2D 15N-heteronuclear single quantum coherence spectra. Degeneracies in the mutual orientation of the protein structures were resolved by the use of two different lanthanide ions, Dy3+ and Er3+.
Pintacuda
Guido
G
Research School of Chemistry, Australian National University, Canberra ACT 0200, Australia.
Park
Ah Young
AY
Keniry
Max A
MA
Dixon
Nicholas E
NE
Otting
Gottfried
G
D004258:DNA Polymerase III / Q000737:chemistry*; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry*; D029968:Escherichia coli Proteins / Q000737:chemistry*; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D017434:Protein Structure, Tertiary; D021122:Protein Subunits
D029968:Escherichia coli Proteins; D028581:Lanthanoid Series Elements; D021122:Protein Subunits; C505238:holE protein, E coli; D004258:DNA Polymerase III; D004259:DNA-Directed DNA Polymerase