Weickhmann, A. Katharina and Keller, Heiko and Wurm, Jan P. and Strebitzer, Elisabeth and Juen, Michael A. and Kremser, Johannes and Weinberg, Zasha and Kreutz, Christoph and Duchardt-Ferner, Elke and Woehnert, Jens (2019) The structure of the SAM/SAH-binding riboswitch. NUCLEIC ACIDS RESEARCH, 47 (5). pp. 2654-2665. ISSN 0305-1048, 1362-4962
Full text not available from this repository. (Request a copy)Abstract
S-adenosylmethionine (SAM) is a central metabolite since it is used as a methyl group donor in many different biochemical reactions. Many bacteria control intracellular SAM concentrations using riboswitch-based mechanisms. A number of structurally different riboswitch families specifically bind to SAM and mainly regulate the transcription or the translation of SAM-biosynthetic enzymes. In addition, a highly specific riboswitch class recognizes S-adenosylhomocysteine (SAH)the product of SAM-dependent methyl group transfer reactionsand regulates enzymes responsible for SAH hydrolysis. High-resolution structures are available for many of these riboswitch classes and illustrate how they discriminate between the two structurally similar ligands SAM and SAH. The so-called SAM/SAH riboswitch class binds both ligands with similar affinities and is structurally not yet characterized. Here, we present a high-resolution nuclear magnetic resonance structure of a member of the SAM/SAH-riboswitch class in complex with SAH. Ligand binding induces pseudoknot formation and sequestration of the ribosome binding site. Thus, the SAM/SAH-riboswitches are translational OFF'-switches. Our results establish a structural basis for the unusual bispecificity of this riboswitch class. In conjunction with genomic data our structure suggests that the SAM/SAH-riboswitches might be an evolutionary late invention and not a remnant of a primordial RNA-world as suggested for other riboswitches.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | S-ADENOSYLMETHIONINE DECARBOXYLASE; HYDROGEN-BONDS; RNA; NMR; ENZYME; ADENOSYLHOMOCYSTEINE; COMPLEXES; BIOSYNTHESIS; NUCLEOSIDASE; COUPLINGS; |
| Subjects: | 500 Science > 570 Life sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Biophysik und physikalische Biochemie > Prof. Dr. Reinhard Sterner |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 20 Apr 2020 08:48 |
| Last Modified: | 20 Apr 2020 08:48 |
| URI: | https://pred.uni-regensburg.de/id/eprint/27353 |
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