Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
A stem-loop structure is a secondary structure formed when single-stranded RNA or DNA folds back on itself, creating a double-stranded stem with an unpaired loop. These structures play critical roles in gene regulation and expression.
5 Must Know Facts For Your Next Test
Stem-loop structures are essential in the termination of transcription in prokaryotes.
They can act as regulatory elements by influencing the stability and translation of mRNA.
The formation of stem-loop structures is influenced by the nucleotide sequence and complementary base pairing.
In the context of operons, stem-loops can function as attenuators to regulate gene expression.
Rho-independent termination involves the formation of a stem-loop followed by a poly-U tail.
A unit of genetic material that functions in coordinated regulation by an operator, promoter, and one or more structural genes.
Attenuator: A regulatory sequence that forms a stem-loop structure to terminate transcription prematurely under certain conditions.
Rho-Independent Termination: A mechanism where transcription is terminated by the formation of a hairpin loop followed by several uracil residues without the need for rho protein.