An up-close look at the pre-mRNA 3'-end processing complex.

Polyadenylation is a nearly universal mRNA processing step in eukaryotic gene expression and it takes place in a macromolecular machinery termed the mRNA 3' processing complex. In a recent study, we reported the purification and comprehensive characterization of functional mammalian mRNA 3' processing complexes. Our study defined the protein composition of this machinery, revealed new potential links between mRNA 3' processing and other cellular processes, and characterized basic structural features of the "core" mRNA 3' processing complex. These results provided new insights into the mechanism of mRNA 3'-end formation.