Download MendeleyStructural Basis for Dynamic Interdomain Movement and RNA Recognition of the Selenocysteine-Specific Elongation Factor Selb.
Ose, T., Soler, N., Rasubala, L., Kuroki, K., Kohda, D., Fourmy, D., Yoshizawa, S., Maenaka, K.(2007) Structure 15: 577
- PubMed: 17502103 Search on PubMed
- DOI: https://doi.org/10.1016/j.str.2007.03.007
- Primary Citation Related Structures:
2UWM - PubMed Abstract:
Selenocysteine (Sec) is the "21st" amino acid and is genetically encoded by an unusual incorporation system. The stop codon UGA becomes a Sec codon when the selenocysteine insertion sequence (SECIS) exists downstream of UGA. Sec incorporation requires a specific elongation factor, SelB, which recognizes tRNA(Sec) via use of an EF-Tu-like domain and the SECIS mRNA hairpin via use of a C-terminal domain (SelB-C). SelB functions in multiple translational steps: binding to SECIS mRNA and tRNA(Sec), delivery of tRNA(Sec) onto an A site, GTP hydrolysis, and release from tRNA and mRNA. However, this dynamic mechanism remains to be revealed. Here, we report a large domain rearrangement in the structure of SelB-C complexed with RNA. Surprisingly, the interdomain region forms new interactions with the phosphate backbone of a neighboring RNA, distinct from SECIS RNA binding. This SelB-RNA interaction is sequence independent, possibly reflecting SelB-tRNA/-rRNA recognitions. Based on these data, the dynamic SelB-ribosome-mRNA-tRNA interactions will be discussed.
- Division of Structural Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan.
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