Back to Search
Start Over
A SAM-I riboswitch with the ability to sense and respond to uncharged initiator tRNA.
- Source :
- Nature Communications; 6/3/2020, Vol. 11 Issue 1, p1-11, 11p
- Publication Year :
- 2020
-
Abstract
- All known riboswitches use their aptamer to senese one metabolite signal and their expression platform to regulate gene expression. Here, we characterize a SAM-I riboswitch (SAM-I<subscript>Xcc</subscript>) from the Xanthomonas campestris that regulates methionine synthesis via the met operon. In vitro and in vivo experiments show that SAM-I<subscript>Xcc</subscript> controls the met operon primarily at the translational level in response to cellular S-adenosylmethionine (SAM) levels. Biochemical and genetic data demonstrate that SAM-I<subscript>Xcc</subscript> expression platform not only can repress gene expression in response to SAM binding to SAM-I<subscript>Xcc</subscript> aptamer but also can sense and bind uncharged initiator Met tRNA, resulting in the sequestering of the anti-Shine-Dalgarno (SD) sequence and freeing the SD for translation initiation. These findings identify a SAM-I riboswitch with a dual functioning expression platform that regulates methionine synthesis through a previously unrecognized mechanism and discover a natural tRNA-sensing RNA element. This SAM-I riboswitch appears to be highly conserved in Xanthomonas species. Riboswitches consist of an aptamer domain and expression platform, which senses a signal and regulates gene expression, respectively. Here the authors show that the expression platform of a SAM-I riboswitch from the Gram-negative bacteria can sense and bind uncharged an initiator Met tRNA to control the met operon. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 20411723
- Volume :
- 11
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Nature Communications
- Publication Type :
- Academic Journal
- Accession number :
- 143571736
- Full Text :
- https://doi.org/10.1038/s41467-020-16417-z