Crystal structure of the human ATP-dependent splicing and export factor UAP56
Shi, H., Cordin, O., Minder, C.M., Linder, P., Xu, R.M.(2004) Proc Natl Acad Sci U S A 101: 17628-17633
- PubMed: 15585580 
- DOI: https://doi.org/10.1073/pnas.0408172101
- Primary Citation of Related Structures:  
1XTI, 1XTJ, 1XTK - PubMed Abstract: 
Pre-mRNA splicing requires the function of a number of RNA-dependent ATPases/helicases, yet no three-dimensional structure of any spliceosomal ATPases/helicases is known. The highly conserved DECD-box protein UAP56/Sub2 is an essential splicing factor that is also important for mRNA export. The expected ATPase/helicase activity appears to be essential for the UAP56/Sub2 functions. Here, we show that purified human UAP56 is an active RNA-dependent ATPase, and we also report the crystal structures of UAP56 alone and in complex with ADP, as well as a DECD to DEAD mutant. The structures reveal a unique spatial arrangement of the two conserved helicase domains, and ADP-binding induces significant conformational changes of key residues in the ATP-binding pocket. Our structural analyses suggest a specific protein-RNA displacement model of UAP56/Sub2. The detailed structural information provides important mechanistic insights into the splicing function of UAP56/Sub2. The structures also will be useful for the analysis of other spliceosomal DExD-box ATPases/helicases.
Organizational Affiliation: 
W. M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.