Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1093/nar/gky709
Licence creative commons licence
Title (Primary) A glutamine riboswitch is a key element for the regulation of glutamine synthetase in cyanobacteria
Author Klähn, S.; Bolay, P.; Wright, P.R.; Atilho, R.M.; Brewer, K.I.; Hagemann, M.; Breaker, R.R.; Hess, W.R.
Source Titel Nucleic Acids Research
Year 2018
Department SOMA
Volume 46
Issue 19
Page From 10082
Page To 10094
Language englisch
Abstract As the key enzyme of bacterial nitrogen assimilation, glutamine synthetase (GS) is tightly regulated. In cyanobacteria, GS activity is controlled by the interaction with inactivating protein factors IF7 and IF17 encoded by the genes gifA and gifB, respectively. We show that a glutamine-binding aptamer within the gifB 5′ UTR of Synechocystis sp. PCC 6803 is critical for the expression of IF17. Binding of glutamine induced structural re-arrangements in this RNA element leading to enhanced protein synthesis in vivo and characterizing it as a riboswitch. Mutagenesis showed the riboswitch mechanism to contribute at least as much to the control of gene expression as the promoter-mediated transcriptional regulation. We suggest this and a structurally related but distinct element, to be designated type 1 and type 2 glutamine riboswitches. Extended biocomputational searches revealed that glutamine riboswitches are exclusively but frequently found in cyanobacterial genomes, where they are primarily associated with gifB homologs. Hence, this RNA-based sensing mechanism is common in cyanobacteria and establishes a regulatory feedback loop that couples the IF17-mediated GS inactivation to the intracellular glutamine levels. Together with the previously described sRNA NsiR4, these results show that non-coding RNA is an indispensable component in the control of nitrogen assimilation in cyanobacteria.
Persistent UFZ Identifier
Klähn, S., Bolay, P., Wright, P.R., Atilho, R.M., Brewer, K.I., Hagemann, M., Breaker, R.R., Hess, W.R. (2018):
A glutamine riboswitch is a key element for the regulation of glutamine synthetase in cyanobacteria
Nucleic Acids Res. 46 (19), 10082 - 10094 10.1093/nar/gky709