NMR resonance assignments for the SAM/SAH-binding riboswitch RNA bound to S-adenosylhomocysteine
- 257 Downloads
Riboswitches are structured RNA elements in the 5′-untranslated regions of bacterial mRNAs that are able to control the transcription or translation of these mRNAs in response to the specific binding of small molecules such as certain metabolites. Riboswitches that bind with high specificity to either S-adenosylmethionine (SAM) or S-adenosylhomocysteine (SAH) are widespread in bacteria. Based on differences in secondary structure and sequence these riboswitches can be grouped into a number of distinct classes. X-ray structures for riboswitch RNAs in complex with SAM or SAH established a structural basis for understanding ligand recognition and discrimination in many of these riboswitch classes. One class of riboswitches—the so-called SAM/SAH riboswitch class—binds SAM and SAH with similar affinity. However, this class of riboswitches is structurally not yet characterized and the structural basis for its unusual bispecificity is not established. In order to understand the ligand recognition mode that enables this riboswitch to bind both SAM and SAH with similar affinities, we are currently determining its structure in complex with SAH using NMR spectroscopy. Here, we present the NMR resonance assignment of the SAM/SAH binding riboswitch (env9b) in complex with SAH as a prerequisite for a solution NMR-based high-resolution structure determination.
KeywordsRNA Riboswitch SAH SAM NMR assignment Triple resonance experiments
We are grateful to Christian Richter and Manfred Strupf for maintenance of the NMR facility and to Kerstin Yacoub for help with sample preparation. This work was supported by the Center for Biomolecular Magnetic Resonance (BMRZ) of the Goethe University Frankfurt and the Deutsche Forschungsgemeinschaft (DFG) through the CRC (SFB) 902 “Molecular principles of RNA-based regulation”, Project B10.
- Chatterjee D, Kudlinzki D, Linhard V, Saxena K, Schieborr U, Gande SL, Wurm JP, Wöhnert J, Abele R, Rogov VV, Dötsch V, Osiewacz HD, Sreeramulu S, Schwalbe H (2015) Structure and biophysical characterization of the S-adenosylmethionine-dependent O-methyltransferase PaMTH1, a putative enzyme accumulating during senescence of Podospora anserina. J Biol Chem 290:16415–16430CrossRefGoogle Scholar
- Keller R (2004) The computer aided resonance tutorial. CANTINA Verlag, GoldauGoogle Scholar
- Sklenár V, Peterson RD, Rejante MR, Feigon J (1994) Correlation of nucleotide base and sugar protons in a 15N-labeled HIV-1 RNA oligonucleotide by 1H-15N HSQC experiments. J Biomol NMR 4:117–122Google Scholar