In:
Nature Communications, Springer Science and Business Media LLC, Vol. 11, No. 1 ( 2020-06-03)
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 Xcc ) from the Xanthomonas campestris that regulates methionine synthesis via the met operon. In vitro and in vivo experiments show that SAM-I Xcc 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 Xcc expression platform not only can repress gene expression in response to SAM binding to SAM-I Xcc 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.
Type of Medium:
Online Resource
ISSN:
2041-1723
DOI:
10.1038/s41467-020-16417-z
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2020
detail.hit.zdb_id:
2553671-0
