H, N and C resonance assignments of a minimal CPSF73-CPSF100 C-terminal heterodimer.

The initial pre-mRNA transcript in eukaryotes is processed by a large multi-protein complex in order to correctly cleave the 3' end, and to subsequently add the polyadenosine tail. This cleavage and polyadenylation specificity factor (CPSF) is composed of separate subunits, with structural information available for both isolated subunits and also larger assembled complexes. Nevertheless, certain key components of CPSF still lack high-resolution atomic data. One such region is the heterodimer formed between the first and second C-terminal domains of the endonuclease CPSF73, with those from the catalytically inactive CPSF100. Here we report the backbone and sidechain resonance assignments of a minimal C-terminal heterodimer of CPSF73-CPSF100 derived from the parasite Encephalitozoon cuniculi. The assignment process used several amino-acid specific labeling strategies, and the chemical shift values allow for secondary structure prediction.