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Domain motions accompanying Tet repressor induction defined by changes of interspin distances at selectively labeled sites.

Tiebel, Beatrix ; Radzwill, N. ; Aung-Hilbrich, L. M. ; Helbl, V. ; Steinhoff, H. J. ; Hillen, W. (1999)
Domain motions accompanying Tet repressor induction defined by changes of interspin distances at selectively labeled sites.
In: Journal of molecular biology, 290 (1)
Artikel, Bibliographie

Kurzbeschreibung (Abstract)

To investigate internal movements in Tet repressor (TetR) during induction by tetracycline (tc) we determined the interspin distances between pairs of nitroxide spin labels attached to specific sites by electron paramagnetic resonance (EPR) spectroscopy. For this purpose, we constructed six TetR variants with engineered cysteine pairs located in regions with presumed conformational changes. These are I22C and N47C in the DNA reading head, T152C/Q175C, A161C/Q175C and R128C/D180C near the tc-binding pocket, and T202C in the dimerization surface. All TetR mutants show wild-type activities in vivo and in vitro. The binding of tc results in a considerable decrease of the distance between the nitroxide groups attached to both I22C residues in the TetR dimer and an increase of the distance between the N47C residues. These opposite effects are consistent with a twisting motion of the DNA reading heads. Changes of the spin-spin interactions between nitroxide groups attached to residues near the tc-binding pocket demonstrate that the C-terminal end of alpha-helix 9 moves away from the protein core upon DNA binding. Alterations of the dipolar interaction between nitroxide groups at T202C indicate different conformations for tc and DNA-bound repressor also in the dimerization area. These results are used to model structural changes of TetR upon induction.

Typ des Eintrags: Artikel
Erschienen: 1999
Autor(en): Tiebel, Beatrix ; Radzwill, N. ; Aung-Hilbrich, L. M. ; Helbl, V. ; Steinhoff, H. J. ; Hillen, W.
Art des Eintrags: Bibliographie
Titel: Domain motions accompanying Tet repressor induction defined by changes of interspin distances at selectively labeled sites.
Sprache: Englisch
Publikationsjahr: 1999
Titel der Zeitschrift, Zeitung oder Schriftenreihe: Journal of molecular biology
Jahrgang/Volume einer Zeitschrift: 290
(Heft-)Nummer: 1
Kurzbeschreibung (Abstract):

To investigate internal movements in Tet repressor (TetR) during induction by tetracycline (tc) we determined the interspin distances between pairs of nitroxide spin labels attached to specific sites by electron paramagnetic resonance (EPR) spectroscopy. For this purpose, we constructed six TetR variants with engineered cysteine pairs located in regions with presumed conformational changes. These are I22C and N47C in the DNA reading head, T152C/Q175C, A161C/Q175C and R128C/D180C near the tc-binding pocket, and T202C in the dimerization surface. All TetR mutants show wild-type activities in vivo and in vitro. The binding of tc results in a considerable decrease of the distance between the nitroxide groups attached to both I22C residues in the TetR dimer and an increase of the distance between the N47C residues. These opposite effects are consistent with a twisting motion of the DNA reading heads. Changes of the spin-spin interactions between nitroxide groups attached to residues near the tc-binding pocket demonstrate that the C-terminal end of alpha-helix 9 moves away from the protein core upon DNA binding. Alterations of the dipolar interaction between nitroxide groups at T202C indicate different conformations for tc and DNA-bound repressor also in the dimerization area. These results are used to model structural changes of TetR upon induction.

Fachbereich(e)/-gebiet(e): 10 Fachbereich Biologie > Synthetic Genetic Circuits (2020 umbenannt in "Synthetic RNA biology")
10 Fachbereich Biologie
Hinterlegungsdatum: 22 Feb 2012 10:48
Letzte Änderung: 05 Mär 2013 09:59
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