Symbol Lysine SO 0000035 | Rfam RF00168 | |
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The Lysine riboswitch is a metabolite binding RNA element found within certain messenger RNAs that serve as a precision sensor for the amino acid lysine. Allosteric rearrangement of mRNA structure is mediated by ligand binding, and this results in modulation of gene expression. This riboswitch is found in a number of genes involved in lysine metabolism, including lysC. The lysine riboswitch has also been identified independently and called the L box.
Structure
The structure of the lysine riboswitch has recently been determined. The lysine amino acid is bound in the pocket formed by the 5-way junction. The structure is composed of a three helical bundle and a two helical bundle joined by the 5-way junction. Helices 1 and 2 are stacked in a colinear fashion as are helices 4 and 5.