Main Page | See live article | Alphabetical index A spliceosome is a complex of RNA and many protein subunits, that remove the non-coding introns from unprocessed mRNA. The mRNA of prokaryotes is simpler, and they do not have introns, so only eukaryotes have spliceosomes. The proteins that spliceosomes consist of are named U1-U6, and have the ability to bind sections of DNA. The RNA part is rich in uridine (the U nucleotides). There are specific 5' and 3' sites on the pre-mRNA that the spliceosome recognises. The area between these locations is spliced out, and the two exons are pasted together. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.