Crystal structure of human UP1, the domain of hnRNP A1 that contains two RNA-recognition motifs.
Xu, R.M., Jokhan, L., Cheng, X., Mayeda, A., Krainer, A.R.(1997) Structure 5: 559-570
- PubMed: 9115444 
- DOI: https://doi.org/10.1016/s0969-2126(97)00211-6
- Primary Citation of Related Structures:  
1UP1 - PubMed Abstract: 
Heterogeneous nuclear ribonucleoprotein (hnRNP) A1 is one of the most abundant core proteins of hnRNP complexes in metazoan nuclei. It behaves as a global regulator of alternative pre-mRNA splicing by antagonizing the activities of several serine/arginine-rich splicing factors (SR proteins), resulting in the activation of distal alternative 5' splice sites and skipping of optional exons. Purified hnRNP A1 has nucleic acid annealing activity. The protein also shuttles continuously between the nucleus and the cytoplasm, a process mediated by signals within its C-terminal glycine-rich domain. The N-terminal region of human hnRNP A1, termed unwinding protein 1 (UP1), contains two RNA-recognition motifs (RRMs), RRM1 and RRM2. Understanding the structural elements by which hnRNP A1 interacts with RNA will have broad implications for studies of RNA processing.
Organizational Affiliation: 
WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, P.O. Box 100, Cold Spring Harbor, New York, 11724, USA. xur@cshl.org