Solution structure of the second RNA recognition motif (RRM) domain of murine T cell intracellular antigen-1 (TIA-1) and its RNA recognition mode
Kuwasako, K., Takahashi, M., Tochio, N., Abe, C., Tsuda, K., Inoue, M., Terada, T., Shirouzu, M., Kobayashi, N., Kigawa, T., Taguchi, S., Tanaka, A., Hayashizaki, Y., Guntert, P., Muto, Y., Yokoyama, S.(2008) Biochemistry 47: 6437-6450
- PubMed: 18500819
- DOI: https://doi.org/10.1021/bi7024723
- Primary Citation of Related Structures:
2RNE - PubMed Abstract:
T cell intracellular antigen-1 (TIA-1), an apoptosis promoting factor, functions as a splicing regulator for the Fas pre-mRNA. TIA-1 possesses three RNA recognition motifs (RRMs) and a glutamine-rich domain. The second RRM (RRM2) is necessary and sufficient for tight, sequence-specific binding to the uridine-rich sequences buried around the 5' splice sites. In the present study, we solved the solution structure of the murine TIA-1 RRM2 by heteronuclear-nuclear magnetic resonance spectroscopy. The TIA-1 RRM2 adopts the RRM fold (betaalphabetabetaalphabeta) and possesses an extra beta-strand between beta2 and beta3, which forms an additional beta-sheet with the C-terminal part of beta2. We refer to this structure as the beta2-beta2' beta-loop. Interestingly, this characteristic beta-loop structure is conserved among a number of RRMs, including the U2AF65 RRM2 and the Sex-lethal RRM1 and RRM2, which also bind to uridine-rich RNAs. Furthermore, we identified a new sequence motif in the beta2-beta2' beta-loop, the DxxT motif. Chemical shift perturbation analyses of both the main and side chains upon binding to the uridine pentamer RNA revealed that most of the beta-sheet surface, including the beta2-beta2' beta-loop, is involved in the RNA binding. An investigation of the chemical shift perturbation revealed similarity in the RNA recognition modes between the TIA-1 and U2AF65 RRMs.
Organizational Affiliation:
Protein Research Group, Genomic Sciences Center, Yokohama Institute, RIKEN, Tsurumi-ku, Yokohama 230-0045, Japan.