Lig RNA thermometer is a cis-acting non-coding RNA element that controls ligA and ligB gene expression in Leptospira interrogans in response to temperature change.

[1] The lipoproteins LigA and LigB stimulate adhesion of the element and then hosting proteins.

[2] The RNA that composes of 175-nucleotide 5'UTR and the first six lig codons (identical in ligA and ligB) folds into two distinct-stem loop structures.

Lig expression is limited by these double-stranded RNA structures because they occludes the ribosome-binding site.

At higher temperatures, the ribosome binding site is exposed to promote translation initiation.