@article{Prasse_Forstner_Jager-sRNA_newly_ident-2017,
author = {Prasse, Daniela and Förstner, Konrad U. and Jäger, Dominik 
          and Backofen, Rolf and Schmitz, Ruth A.},
title = {{sRNA154} a newly identified regulator of nitrogen fixation 
         in {Methanosarcina} mazei strain {Go1}},
journal = {RNA Biol},
year = {2017},
doi = {10.1080/15476286.2017.1306170},
volume = {13},
user = {backofen},
pmid = {28296572},
pages = {1544-58},
number = {11},
issn = {1547-6286},
abstract = {Trans-encoded sRNA154 is exclusively expressed under 
            nitrogen (N)-deficiency in Methanosarcina mazei strain Go1. 
            The sRNA154 deletion strain showed a significant decrease in 
            growth under N-limitation, pointing toward a regulatory role 
            of sRNA154 in N-metabolism. Aiming to elucidate its 
            regulatory function we characterized sRNA154 by means of 
            biochemical and genetic approaches. 24 homologs of sRNA154 
            were identified in recently reported draft genomes of 
            Methanosarcina strains, demonstrating high conservation in 
            sequence and predicted secondary structure with two highly 
            conserved single stranded loops. Transcriptome studies of 
            sRNA154 deletion mutants by an RNA-seq approach uncovered 
            nifH- and nrpA-mRNA, encoding the alpha-subunit of 
            nitrogenase and the transcriptional activator of the 
            nitrogen fixation (nif)-operon, as potential targets besides 
            other components of the N-metabolism. Furthermore, results 
            obtained from stability, complementation and western blot 
            analysis, as well as in silico target predictions combined 
            with electrophoretic mobility shift-assays, argue for a 
            stabilizing effect of sRNA154 on the polycistronic nif-mRNA 
            and nrpA-mRNA by binding with both loops. Further identified 
            N-related targets were studied, which demonstrates that 
            translation initiation of glnA2-mRNA, encoding glutamine 
            synthetase2, appears to be affected by sRNA154 masking the 
            ribosome binding site, whereas glnA1-mRNA appears to be 
            stabilized by sRNA154. Overall, we propose that sRNA154 has 
            a crucial regulatory role in N-metabolism in M. mazei by 
            stabilizing the polycistronic mRNA encoding nitrogenase and 
            glnA1-mRNA, as well as allowing a feed forward regulation of 
            nif-gene expression by stabilizing nrpA-mRNA. Consequently, 
            sRNA154 represents the first archaeal sRNA, for which a 
            positive posttranscriptional regulation is demonstrated as 
            well as inhibition of translation initiation.}
}