Efficient chi-tensor determination and NH assignment of paramagnetic proteins.
Anisotropic magnetic susceptibility tensors chi of paramagnetic metal ions are manifested in pseudocontact shifts, residual dipolar couplings, and other paramagnetic observables that present valuable long-range information for structure determinations of protein-ligand complexes. A program was developed for automatic determination of the chi-tensor anisotropy parameters and amide resonance assignments in proteins labeled with paramagnetic metal ions. The program requires knowledge of the three-dimensional structure of the protein, the backbone resonance assignments of the diamagnetic protein, and a pair of 2D 15N-HSQC or 3D HNCO spectra recorded with and without paramagnetic metal ion. It allows the determination of reliable chi-tensor anisotropy parameters from 2D spectra of uniformly 15N-labeled proteins of fairly high molecular weight. Examples are shown for the 185-residue N-terminal domain of the subunit epsilon from E. coli DNA polymerase III in complex with the subunit theta and La3+ in its diamagnetic and Dy3+, Tb3+, and Er3+ in its paramagnetic form.
Schmitz
Christophe
C
Department of Mathematics, University of Queensland, Brisbane, QLD, 4072, Australia.
John
Michael
M
Park
Ah Young
AY
Dixon
Nicholas E
NE
Otting
Gottfried
G
Pintacuda
Guido
G
Huber
Thomas
T
D000465:Algorithms; D016880:Anisotropy; D004258:DNA Polymerase III / Q000737:chemistry; D004926:Escherichia coli / Q000201:enzymology; D028581:Lanthanoid Series Elements / Q000737:chemistry; D008280:Magnetics; D008667:Metalloproteins / Q000737:chemistry*; D009587:Nitrogen Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D021122:Protein Subunits / Q000737:chemistry; D012984:Software
D028581:Lanthanoid Series Elements; D008667:Metalloproteins; D009587:Nitrogen Isotopes; D021122:Protein Subunits; D004258:DNA Polymerase III