The TRAMP complex (Trf4/Air2/Mtr4p Polyadenylation complex) is a multi-protein complex consisting of the RNA helicase (Mtr4/Dob1), a poly(A) polymerase (PAP) (either Trf4 or Trf5) and a zinc knuckle protein (either Air1 or Air2). The TRAMP complex interacts with the exosome complex in the nucleus of eukaryotic cells and is involved in the 3' end processing and degradation of ribosomal RNA and snoRNAs.
Originally discovered in the yeast Saccharomyces cerevisiae, the TRAMP complex trims the poly(A) tails of RNAs destined for Rrp6 and the core exosome down to 4-5 adenosines, assisting in transcript recognition and exosome complex activation. In this way, TRAMP plays a critical role in ridding the cell of noncoding transcripts generated through pervasive RNA polymerase II transcription, as well as functioning in the biogenesis and turnover of functional coding and noncoding RNAs.