2pjp
From Proteopedia
Structure of the mRNA-binding domain of elongation factor SelB from E.coli in complex with SECIS RNA
Structural highlights
FunctionSELB_ECOLI Translation factor necessary for the incorporation of selenocysteine into proteins. It probably replaces EF-Tu for the insertion of selenocysteine directed by the UGA codon. SelB binds GTP and GDP. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedElongation factor SelB is responsible for co-translational incorporation of selenocysteine (Sec) into proteins. The UGA stop codon is recoded as a Sec codon in the presence of a downstream mRNA hairpin. In prokaryotes, in addition to the EF-Tu-like N-terminal domains, a C-terminal extension containing four tandem winged-helix motifs (WH1-4) recognizes the mRNA hairpin. The 2.3-A resolution crystal structure of the Escherichia coli WH3/4 domains bound to mRNA with mutagenesis data reveal that the two WH motifs use the same structural elements to bind RNA. The structure together with the 2.6-A resolution structure of the WH1-4 domains from Moorella thermoacetica bound to RNA revealed that a salt bridge connecting WH2 to WH3 modules is disrupted upon mRNA binding. The results provide a structural basis for the molecular switch that may allow communication between tRNA and mRNA binding sites and illustrate how RNA acts as an activator of the switch. The structures show that tandem WH motifs not only provide an excellent scaffold for RNA binding but can also have an active role in the function of protein-RNA complexes. Structural insight into a molecular switch in tandem winged-helix motifs from elongation factor SelB.,Soler N, Fourmy D, Yoshizawa S J Mol Biol. 2007 Jul 20;370(4):728-41. Epub 2007 May 10. PMID:17537456[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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