Download MendeleyMolecular basis for the recognition of the human AAUAAA polyadenylation signal.
Sun, Y., Zhang, Y., Hamilton, K., Manley, J.L., Shi, Y., Walz, T., Tong, L.(2018) Proc Natl Acad Sci U S A 115: E1419-E1428
- PubMed: 29208711
- DOI: https://doi.org/10.1073/pnas.1718723115
- Primary Citation of Related Structures:
6BLY, 6BM0, 6DNH - PubMed Abstract:
Nearly all eukaryotic messenger RNA precursors must undergo cleavage and polyadenylation at their 3'-end for maturation. A crucial step in this process is the recognition of the AAUAAA polyadenylation signal (PAS), and the molecular mechanism of this recognition has been a long-standing problem. Here, we report the cryo-electron microscopy structure of a quaternary complex of human CPSF-160, WDR33, CPSF-30, and an AAUAAA RNA at 3.4-Å resolution. Strikingly, the AAUAAA PAS assumes an unusual conformation that allows this short motif to be bound directly by both CPSF-30 and WDR33. The A1 and A2 bases are recognized specifically by zinc finger 2 (ZF2) of CPSF-30 and the A4 and A5 bases by ZF3. Interestingly, the U3 and A6 bases form an intramolecular Hoogsteen base pair and directly contact WDR33. CPSF-160 functions as an essential scaffold and preorganizes CPSF-30 and WDR33 for high-affinity binding to AAUAAA. Our findings provide an elegant molecular explanation for how PAS sequences are recognized for mRNA 3'-end formation.
Organizational Affiliation:
Department of Biological Sciences, Columbia University, New York, NY 10027.
