In
molecular biology
Molecular biology is a branch of biology that seeks to understand the molecule, molecular basis of biological activity in and between Cell (biology), cells, including biomolecule, biomolecular synthesis, modification, mechanisms, and interactio ...
, the coronavirus
frameshifting stimulation element is a
conserved stem-loop
Stem-loops are nucleic acid Biomolecular structure, secondary structural elements which form via intramolecular base pairing in single-stranded DNA or RNA. They are also referred to as hairpins or hairpin loops. A stem-loop occurs when two regi ...
of
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 ...
found in
coronavirus
Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the comm ...
es that can promote
ribosomal frameshifting. Such RNA molecules interact with a
downstream region to form a
pseudoknot
__NOTOC__
A pseudoknot is a nucleic acid secondary structure containing at least two stem-loop structures in which half of one stem is intercalated between the two halves of another stem. The pseudoknot was first recognized in the turnip yellow ...
structure; the region varies according to the virus but pseudoknot formation is known to stimulate
frameshifting. In the classical situation, a sequence 32
nucleotide
Nucleotides are Organic compound, organic molecules composed of a nitrogenous base, a pentose sugar and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both o ...
s downstream of the stem is complementary to part of the loop. In other coronaviruses, however, another stem-loop structure around 150 nucleotides downstream can interact with members of this family to form
kissing stem-loops and stimulate frameshifting.
Other RNA families identified in the coronavirus include the
coronavirus 3′ stem-loop II-like motif (s2m), the
coronavirus packaging signal and the
coronavirus 3′ UTR pseudoknot.
During protein synthesis, rapidly changing conditions in the cell can cause
ribosomal pausing. In coronaviruses, this can affect growth rate and trigger translational abandonment. This releases the ribosome from the mRNA and the incomplete polypeptide is targeted for destruction.
See also
*
Translational frameshift
Ribosomal frameshifting, also known as translational frameshifting or translational recoding, is a biological phenomenon that occurs during translation that results in the production of multiple, unique proteins from a single mRNA. The process can ...
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Slippery sequence
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Coronavirus 5′ UTR
*
Coronavirus 3′ UTR
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Coronavirus 3′ UTR pseudoknot
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Coronavirus 3′ stem-loop II-like motif (s2m)
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Coronavirus packaging signal
References
External links
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Cis-regulatory RNA elements
Coronaviridae
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