The histone 3′ UTR stem-loop is an RNA element involved in nucleocytoplasmic transport of the

histone In biology, histones are highly basic proteins abundant in lysine and arginine residues that are found in eukaryotic cell nuclei. They act as spools around which DNA winds to create structural units called nucleosomes. Nucleosomes in turn are wr ...

mRNAs, and in the regulation of stability and of translation efficiency in the

cytoplasm In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The ...

. The

mRNA In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of Protein biosynthesis, synthesizing a protein. mRNA is ...

s of

metazoan Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, ca ...

genes lack

polyadenylation Polyadenylation is the addition of a poly(A) tail to an RNA transcript, typically a messenger RNA (mRNA). The poly(A) tail consists of multiple adenosine monophosphates; in other words, it is a stretch of RNA that has only adenine bases. In euk ...

and a

poly-A tail Polyadenylation is the addition of a poly(A) tail to an RNA transcript, typically a messenger RNA (mRNA). The poly(A) tail consists of multiple adenosine monophosphates; in other words, it is a stretch of RNA that has only adenine bases. In euka ...

, instead 3′ end processing occurs at a site between this highly conserved stem-loop and a

purine Purine is a heterocyclic compound, heterocyclic aromatic organic compound that consists of two rings (pyrimidine and imidazole) fused together. It is water-soluble. Purine also gives its name to the wider class of molecules, purines, which includ ...

rich region around 20

nucleotide 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 wi ...

s downstream (the histone downstream element, or HDE). The

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 ...

is bound by a 31 kDa stem-loop binding protein (

SLBP Histone RNA hairpin-binding protein or stem-loop binding protein (SLBP) is a protein that in humans is encoded by the ''SLBP'' gene. Species distribution SLBP has been cloned from humans, ''C. elegans'', ''D. melanogaster'', '' X. laevis'', a ...

- also termed the histone hairpin binding protein, or HBP). Together with U7 snRNA binding of the HDE, SLBP binding nucleates the formation of the processing complex.

References

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External links

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Transterm page for Histone 3′ stem loop

UTRSite page for Histone 3′UTR stem-loop structure (HSL3)
Cis-regulatory RNA elements {{molecular-cell-biology-stub