U12 minor spliceosomal RNA is formed from U12 small nuclear ( snRNA), together with U4atac/ U6atac, U5, and U11 snRNAs and associated proteins, forms a

spliceosome A spliceosome is a large ribonucleoprotein (RNP) complex found primarily within the nucleus of eukaryotic cells. The spliceosome is assembled from small nuclear RNAs ( snRNA) and numerous proteins. Small nuclear RNA (snRNA) molecules bind to sp ...

that cleaves a divergent class of low-abundance pre-

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 ...

intron An intron is any nucleotide sequence within a gene that is not expressed or operative in the final RNA product. The word ''intron'' is derived from the term ''intragenic region'', i.e., a region inside a gene."The notion of the cistron .e., gen ...

s. Although the U12 sequence is very divergent from that of U2, the two are functionally analogous.

Structure

The predicted

secondary structure Protein secondary structure is the local spatial conformation of the polypeptide backbone excluding the side chains. The two most common Protein structure#Secondary structure, secondary structural elements are alpha helix, alpha helices and beta ...

of U12 RNA is published,. However, the alternative single hairpin in the 3' end shown here seems to better match the alignment of divergent ''

Drosophila melanogaster ''Drosophila melanogaster'' is a species of fly (an insect of the Order (biology), order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly", "pomace fly" ...

'' and ''

Arabidopsis thaliana ''Arabidopsis thaliana'', the thale cress, mouse-ear cress or arabidopsis, is a small plant from the mustard family (Brassicaceae), native to Eurasia and Africa. Commonly found along the shoulders of roads and in disturbed land, it is generally ...

'' sequences. The sequences U12 introns that are spliced out are collected in a

biological database Biological databases are libraries of biological sciences, collected from scientific experiments, published literature, high-throughput experiment technology, and computational analysis. They contain information from research areas including geno ...

called the U12 intron database.

References

External links

* Small nuclear RNA Spliceosome RNA splicing {{molecular-cell-biology-stub