A complete relaxation matrix refinement of the solution structure of a paramagnetic metalloprotein: Reduced HiPIP I fromEctothiorhodospira halophila

✍ Scribed by Bertini, Ivano; Felli, Isabella C.; Luchinat, Claudio; Rosato, Antonio

• Book ID: 102648359
• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 698 KB
• Volume: 24
• Category: Article
• ISSN: 0887-3585
• DOI: 10.1002/(sici)1097-0134(199602)24:2<158::aid-prot3>3.0.co;2-f

✦ Synopsis

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 IS0 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 A for backbone atoms and from 1.23 to 1.06 di 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.