Long-Range Motional Restrictions in a Multidomain Zinc-Finger Protein from Anisotropic Tumbling

• Published in: Science (American Association for the Advancement of Science) Vol. 268; no. 5212; pp. 886 - 889
• Main Authors: Brüschweiler, Rafael, Liao, Xiubei, Wright, Peter E.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 12.05.1995; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: Anisotropy; Biochemistry; Biological and medical sciences; Correlations; DNA-Binding Proteins - chemistry; Ellipsoids; Fundamental and applied biological sciences. Psychology; Goodness of Fit; Kinetics; Least Squares Statistics; Magnetic Resonance Spectroscopy; Mathematics; Medical imaging; Models, Molecular; Molecular biophysics; Molecules; Nuclear magnetic resonance; Nuclear magnetic resonance spectroscopy; Principals; Protein Conformation; Protein structure; Proteins; Proteins - chemistry; Rotation; Solutions; Structure; Structure in molecular biology; Tensors; Transcription Factor TFIIIA; Transcription Factors - chemistry; Tridimensional structure; Xenopus; Zinc; Zinc Fingers; Vertebrata; Molecular orientation; Three dimensional structure; Zinc finger structure; Xenopus laevis; Amphibia; Salientia; Transcription factor TFIIIA; Molecular domain; Structural analysis; Conformation
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.7754375

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 $^{15}$N-$^1$H. 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.