| Type: | Domain | Name: | CID domain |
| Description: | The C-terminal domain (CTD) of the large subunit of RNA polymerase II is a platform for mRNA processing factors and links gene transcription to mRNAcapping, splicing and polyadenylation. CTD recognition is dependent on the phosphorylation state of the CTD itself, which varies during the course oftranscription but has also been linked to the isomerization state of the CTD's proline residues. Several RNA-processing factors recognise the CTD by means ofa conserved CTD-interacting domain (CID). Factors with CID domains include the serine/arginine-rich-like factors SCAF4 and SCAF8, Nrd1 (which is implicatedin polyadenylation-independent RNA 3'-end formation) and Pcf11. Pcf11 is a conserved and essential subunit of the yeast cleavage factor 1A, which isrequired for 3'-RNA processing and transcription termination [, ].The CID domain is a right-handed superhelix of eight alpha-helices forming a compact domain. The CID fold closely resembles that of VHSdomains and is related to armadillo-repeat proteins , except for the two amino-terminal helices. Amino acid residues in the hydrophobic core of the domain are highly conserved across CID domains[, ]. | Short Name: | CID_dom |
