Long-range motional restrictions in a multidomain zinc-finger protein from anisotropic tumbling.
Structural characterization of biomolecules in solution by nuclear magnetic resonance (NMR) spectroscopy is based primarily on the use of interproton distances derived from homonuclear cross-relaxation experiments. Information about short time-scale dynamics, on the other hand, is obtained from relaxation rates of heteronuclear spin pairs such as 15N-1H. By combining the two types of data and utilizing the dependence of heteronuclear NMR relaxation rates on anisotropic diffusional rotational tumbling, it is possible to obtain structural information about long-range motional correlations between protein domains. This approach was applied to characterize the relative orientations and mobilities of the first three zinc-finger domains of the Xenopus transcription factor TFIIIA in aqueous solution. The data indicate that the motions of the individual zinc-finger domains are highly correlated on time scales shorter than 10 nanoseconds and that the average conformation of the three-finger polypeptide is elongated.
Brüschweiler
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Laboratorium für Physikalische Chemie, Eidgenössiche Technische Hochschule Zentrum, Zürich, Switzerland.
Liao
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Wright
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PE
D016880:Anisotropy; D004268:DNA-Binding Proteins / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008433:Mathematics; D008958:Models, Molecular; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry; D012996:Solutions; D035582:Transcription Factor TFIIIA; D014157:Transcription Factors / Q000737:chemistry*; D016335:Zinc Fingers
D004268:DNA-Binding Proteins; D011506:Proteins; D012996:Solutions; D035582:Transcription Factor TFIIIA; D014157:Transcription Factors; C079406:ZF-1 protein, Sus scrofa