1lva
Crystal structure of a C-terminal fragment of Moorella thermoacetica elongation factor SelB
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OverviewOverview
SelB is an elongation factor needed for the co-translational incorporation of selenocysteine. Selenocysteine is coded by a UGA stop codon in combination with a specific downstream mRNA hairpin. In bacteria, the C-terminal part of SelB recognizes this hairpin, while the N-terminal part binds GTP and tRNA in analogy with elongation factor Tu (EF-Tu). We present the crystal structure of a C-terminal fragment of SelB (SelB-C) from Moorella thermoacetica at 2.12 A resolution, solved by a combination of selenium and yttrium multiwavelength anomalous dispersion. This 264 amino acid fragment contains the entire C-terminal extension beginning after the EF-Tu-homologous domains. SelB-C consists of four similar winged-helix domains arranged into the shape of an L. This is the first example of winged-helix domains involved in RNA binding. The location of conserved basic amino acids, together with data from the literature, define the position of the mRNA-binding site. Steric requirements indicate that a conformational change may occur upon ribosome interaction. Structural observations and data in the literature suggest that this change happens upon mRNA binding.
About this StructureAbout this Structure
1LVA is a Single protein structure of sequence from Moorella thermoacetica with and as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of an mRNA-binding fragment of Moorella thermoacetica elongation factor SelB., Selmer M, Su XD, EMBO J. 2002 Aug 1;21(15):4145-53. PMID:12145214
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