TY  - JOUR
A1  - Wacker, Anna
A1  - Buck, Janina
A1  - Mathieu, Daniel
A1  - Richter, Christian
A1  - Wöhnert, Jens
A1  - Schwalbe, Harald
T1  - Structure and dynamics of the deoxyguanosine-sensing riboswitch studied by NMR-spectroscopy
T2  - Nucleic acids research
N2  - The mfl-riboswitch regulates expression of ribonucleotide reductase subunit in Mesoplasma florum by binding to 2´-deoxyguanosine and thereby promoting transcription termination. We characterized the structure of the ligand-bound aptamer domain by NMR spectroscopy and compared the mfl-aptamer to the aptamer domain of the closely related purine-sensing riboswitches. We show that the mfl-aptamer accommodates the extra 2´-deoxyribose unit of the ligand by forming a more relaxed binding pocket than these found in the purine-sensing riboswitches. Tertiary structures of the xpt-aptamer bound to guanine and of the mfl-aptamer bound to 2´-deoxyguanosine exhibit very similar features, although the sequence of the mfl-aptamer contains several alterations compared to the purine-aptamer consensus sequence. These alterations include the truncation of a hairpin loop which is crucial for complex formation in all purine-sensing riboswitches characterized to date. We further defined structural features and ligand binding requirements of the free mfl-aptamer and found that the presence of Mg2+ is not essential for complex formation, but facilitates ligand binding by promoting pre-organization of key structural motifs in the free aptamer.
Y1  - 2011
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/22411
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30-106495
SN  - 1362-4962
SN  - 0305-1048
N1  - © 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  - 39
IS  - 15
SP  - 6802
EP  - 6812
PB  - Oxford Univ. Press
CY  - Oxford
ER  -