RncO is a bacterial

non-coding RNA A non-coding RNA (ncRNA) is a functional RNA molecule that is not translated into a protein. The DNA sequence from which a functional non-coding RNA is transcribed is often called an RNA gene. Abundant and functionally important types of non-c ...

regulatory element found in the rnc leader sequence. The rnc

operon In genetics, an operon is a functioning unit of DNA containing a cluster of genes under the control of a single promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo splic ...

is negatively auto-regulated by transcript stability. ''rnc'', the first gene in the operon codes for

RNase III Ribonuclease III (RNase III or RNase C)(BREND3.1.26.3 is a type of ribonuclease that recognizes dsRNA and cleaves it at specific targeted locations to transform them into mature RNAs. These enzymes are a group of endoribonucleases that are chara ...

which cleaves the long rncO

stem Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushro ...

II leading to transcript degradation and a reduction in translation. Matsunaga ''et al.'' showed that

cleavage can initiate rnc transcript decay independently of rnc gene translation. Further work has established that rncO structure and function is conserved in ''

Salmonella typhimurium ''Salmonella enterica'' subsp. ''enterica'' is a subspecies of ''Salmonella enterica'', the rod-shaped, flagellated, aerobic, Gram-negative bacterium. Many of the pathogenic serovars of the ''S. enterica'' species are in this subspecies, includi ...

''.

Structure

Functionally the first 215

nucleotides Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules w ...

of the rnc leader have been shown to be sufficient. Within this region three

stem-loop Stem-loop intramolecular base pairing is a pattern that can occur in single-stranded RNA. The structure is also known as a hairpin or hairpin loop. It occurs when two regions of the same strand, usually complementary in nucleotide sequence when ...

s were identified. Stem-loop II is cleaved by RNase III, whereas stem-loops I and III are important for stability.

References

External links

* Cis-regulatory RNA elements {{molecular-cell-biology-stub