description
The 3' ends of eukaryotic mRNAs are generated by posttranscriptional processing of an extended primary transcript. For almost all RNAs, 3'-end processing consists of two steps: (i) the mRNA is first cleaved at a particular phosphodiester bond downstream of the coding sequence, (ii) the upstream fragment then receives a poly(A) tail of approximately 250 adenylate residues, whereas the downstream fragment is degraded. The two partial reactions are coupled so that reaction intermediates are usually undetectable. While 3' processing can be studied as an isolated event in vitro, it appears to be connected to transcription, splicing, and transcription termination in vivo.The only known exception to the rule of cleavage followed by polyadenylation are the major histone mRNAs, which are cleaved but not polyadenylated

external resources
NCBI:1269692
REACTOME:R-HSA-72187
PUBMED:10371034
PUBMED:10357856
PUBMED:2408761
PUBMED:11909521

genes
CSTF1 , CSTF2 , CSTF3 , MAGOH , NCBP1 , SRSF1 , SRSF2 , SRSF3 , SRSF4 , SRSF5 , SRSF6 , SRSF7 , U2AF1 , DDX39B , PABPN1 , SYMPK , THOC5 , SRSF9 , SRSF11 , EIF4A3 , DHX38 , ZC3H11A , RBM8A , THOC1 , ALYREF , DDX39A , SRRM1 , SLU7 , CPSF4 , PAPOLA , RNPS1 , CLP1 , NUDT21 , U2AF2 , CASC3 , NCBP2 , CSTF2T , CHTOP , CPSF1 , LUZP4 , CDC40 , PCF11 , CPSF3 , CPSF2 , MAGOHB , WDR33 , THOC2 , UPF3B , THOC6 , CPSF7 , THOC7 , FIP1L1 , FYTTD1 , POLDIP3 , THOC3 , SARNP , U2AF1L4 , MIR636 , MIR939 , MIR1234 ,