ISSN:
0887-3585
Keywords:
NMR
;
iron-sulfur proteins
;
nuclear Overhauser effect
;
paramagnetic relaxation
;
relaxation matrix analysis
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
We have accounted for the effect of paramagnetism on the intensities of NOEs in a 73-residue paramagnetic metalloprotein, the reduced high-potential iron sulfur protein ISO I from Ectothiorhodospira halophila, whose solution structure had been recently solved by us. The paramagnetic effects were dealt with through a suitably modified complete relaxation matrix approach. We have then recalculated the structure through a distance geometry program by minimizing the difference between the sixth roots of the calculated and experimental NOEs.The average RMSD, calculated on residues 4-71, within the structures constituting the two families decreased from 0.67 to 0.46 Å for backbone atoms and from 1.23 to 1.06 Å for all heavy atoms. The structures in the new family are for the most part within the indetermination of the previous, less resolved, family. A few specific differences are detected and related to the presence of non-negligible paramagnetic effects, which are now properly evaluated.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
