The ''aspS'' RNA motif is a conserved

RNA Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...

structure that was discovered by bioinformatics. ''aspS'' motifs are found in a specific lineage of

Actinomycetota The Actinomycetota (or Actinobacteria) are a diverse phylum of Gram-positive bacteria with high GC content. They can be terrestrial or aquatic. They are of great importance to land flora because of their contributions to soil systems. In soil t ...

. ''aspS'' motif RNAs likely function as

cis-regulatory element ''Cis''-regulatory elements (CREs) or ''cis''-regulatory modules (CRMs) are regions of non-coding DNA which regulate the transcription of neighboring genes. CREs are vital components of genetic regulatory networks, which in turn control morpho ...

s, in view of their positions upstream of protein-coding

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

s. Instances of the ''aspS'' RNA motif are often located nearby to the predicted Shine-Dalgarno sequence of the downstream gene. This arrangement is consistent with a model of ''cis''-regulation where the RNA allosterically controls access to the Shine-Dalgarno sequence, thus regulating the gene translationally. ''aspS'' genes encode

aminoacyl tRNA synthetase An aminoacyl-tRNA synthetase (aaRS or ARS), also called tRNA-ligase, is an enzyme that attaches the appropriate amino acid onto its corresponding tRNA. It does so by catalyzing the transesterification of a specific cognate amino acid or its pre ...

s. T-box leader RNAs detect low levels of various

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...

s, and regulate genes in a ''cis''-regulatory manner. Genes regulated by T-box RNAs often include aminoacyl tRNA synthetases. It is possible that ''aspS'' RNAs are diverged examples of T-box RNAs, or they might implement a different structural solution to the same biological problem.

References

{{reflist Non-coding RNA