TY  - JOUR
A1  - Förster, Ute
A1  - Weigand, Julia E.
A1  - Trojanowski, Peter
A1  - Süß, Beatrix
A1  - Wachtveitl, Josef
T1  - Conformational dynamics of the tetracycline-binding aptamer
T2  - Nucleic acids research
N2  - The conformational dynamics induced by ligand binding to the tetracycline-binding aptamer is monitored via stopped-flow fluorescence spectroscopy and time-correlated single photon counting experiments. The fluorescence of the ligand is sensitive to changes within the tertiary structure of the aptamer during and after the binding process. In addition to the wild-type aptamer, the mutants A9G, A13U and A50U are examined, where bases important for regulation are changed to inhibit the aptamer’s function. Our results suggest a very fast two-step-mechanism for the binding of the ligand to the aptamer that can be interpreted as a binding step followed by a reorganization of the aptamer to accommodate the ligand. Binding to the two direct contact points A13 and A50 was found to occur in the first binding step. The exchange of the structurally important base A9 for guanine induces an enormous deceleration of the overall binding process, which is mainly rooted in an enhancement of the back reaction of the first binding step by several orders of magnitude. This indicates a significant loss of tertiary structure of the aptamer in the absence of the base A9, and underlines the importance of pre-organization on the overall binding process of the tetracycline-binding aptamer.
Y1  - 2011
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/25008
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-250088
UR  - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3287181/
SN  - 1362-4962
SN  - 0305-1048
N1  - (c) The Author(s) 2011. Published by Oxford University Press. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
VL  - 40
IS  - 4
SP  - 1807
EP  - 1817
PB  - Oxford Univ. Press
CY  - Oxford
ER  -