Structure of the RBM7-ZCCHC8 core of the NEXT complex reveals connections to splicing factors.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 27905398.
- Also identified by DOI 10.1038/ncomms13573 and PMC identifier 5146272.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The eukaryotic RNA exosome participates extensively in RNA processing and degradation. In human cells, three accessory factors (RBM7, ZCCHC8 and hMTR4) interact to form the nuclear exosome targeting (NEXT) complex, which directs a subset of non-coding RNAs for exosomal degradation. Here we elucidate how RBM7 is incorporated in the NEXT complex. We identify a proline-rich segment of ZCCHC8 as the interaction site for the RNA-recognition motif (RRM) of RBM7 and present the crystal structure of the corresponding complex at 2.0 Å resolution. On the basis of the structure, we identify a proline-rich segment within the splicing factor SAP145 with strong similarity to ZCCHC8. We show that this segment of SAP145 not only binds the RRM region of another splicing factor SAP49 but also the RRM of RBM7. These dual interactions of RBM7 with the exosome and the spliceosome suggest a model whereby NEXT might recruit the exosome to degrade intronic RNAs.
Medical subject headings
- Carrier Proteins
- Multiprotein Complexes
- Nuclear Proteins
- RNA Splicing Factors
- RNA-Binding Proteins