Chemical shift assignments of a new folded domain from yeast Pcf11

The yeast protein Pcf11 is a component of the cleavage/polyadenylation factor IA (CF IA) complex involved in the 3' processing of pre-mRNA. Pcf11 interacts with RNA and the C-terminal domain (CTD) of the largest subunit of RNA polymerase II via the CTD-interaction domain (CID), and other peptide regions mediate contacts with CF IA subunits Clp1 and Rna14/Rna15. We have identified a novel domain adjacent to the CID and have determined the backbone and sidechain (1)H, (13)C and (15)N chemical shift assignments for the bacterially produced construct. Despite the reduced sequence complexity due to numerous glutamine and leucine residues, secondary chemical shift analysis indicates that the domain is composed of three well-defined helical regions with relaxation measurements consistent with a folded independent domain. The proximity of this previously uncharacterized domain close to the N-terminal CID prompts speculation for a putative role in modulating CTD and RNA binding, or possible intermolecular contacts within CF IA.