Folding of the lysine riboswitch: importance of peripheral elements for transcriptional regulation.

ABSTRACT: The Bacillus subtilis lysC lysine riboswitch modulates its own gene expression upon lysine binding through a transcription attenuation mechanism. The riboswitch aptamer is organized around a single five-way junction that provides the scaffold for two long-range tertiary interactions (loop L2-loop L3 and helix P2-loop L4)--all of this for the creation of a specific lysine binding site. We have determined that the interaction P2-L4 is particularly important for the organization of the ligand-binding site and for the riboswitch transcription attenuation control. Moreover, we have observed that a folding synergy between L2-L3 and P2-L4 allows both interactions to fold at lower magnesium ion concentrations. The P2-L4 interaction is also critical for the close juxtaposition involving stems P1 an

SUBMITTER: Blouin S 

PROVIDER: S-EPMC3082890 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature