Structural model for the selenocysteine-specific elongation factor SelB.

R Hilgenfeld; A Böck; R Wilting

doi:10.1016/s0300-9084(97)86719-3

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Structural model for the selenocysteine-specific elongation factor SelB.

R Hilgenfeld·A Böck·R Wilting

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Abstract

A structural model was established for the N-terminal part of translation factor SelB which shares sequence similarity with EF-Tu, taking into account the coordinates of the EF-Tu 3D structure and the consensus of SelB sequences from four bacteria. The model showed that SelB is homologous in its N-terminal domains over all three domains of EF-Tu. The guanine nucleotide binding site and the residues involved in GTP hydrolysis are similar to those of EF-Tu, but with some subtle differences possibly responsible for the higher affinity of SelB for GTP compared to GDP. In accordance, the EF-Tu epitopes interacting with EF-Ts are lacking in SelB. Information on the formation of the selenocysteyl-binding pocket is presented. A phylogenetic comparison of the SelB domains homologous to EF-Tu with those from EF-Tu and initiation factor 2 indicated that SelB forms a separate class of translation factors.

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Amino Acid Sequence Bacterial Proteins Computer Simulation Crystallography, X-Ray Escherichia coli Models, Molecular Molecular Sequence Data Peptide Elongation Factor Tu Peptide Elongation Factors Phylogeny Protein Structure, Secondary Selenocysteine Sequence Alignment Sequence Homology, Amino Acid Thermus thermophilus Comparative Study Journal Article Research Support, Non-U.S. Gov't

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R Hilgenfeld, A Böck, R Wilting. 1996. Structural model for the selenocysteine-specific elongation factor SelB.. https://doi.org/10.1016/s0300-9084(97)86719-3

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