Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
, 312, 17-25

Regulation of Gene Expression by Stop Codon Recoding: Selenocysteine

Affiliations
Review

Regulation of Gene Expression by Stop Codon Recoding: Selenocysteine

Paul R Copeland. Gene.

Abstract

The regulation of gene expression at the translational level not only allows for rapid changes in specific protein levels but also provides an opportunity to alter codon specificity. For the incorporation of selenocysteine (Sec) into protein, the UGA codon is transformed from one that signals translation termination to one specific for Sec. This review provides a look at Sec incorporation from the perspective of the individual steps involved in protein synthesis: initiation, elongation and termination. The roles of the factors known to be required for Sec incorporation are considered in the context of each step in translation including structural modeling of the differences between the standard elongation factor eEF1A and the Sec-specific counterpart, eEFSec.

Figures

Fig. 1
Fig. 1
SECIS element of phospholipid hydroperoxide glutathione peroxidase. Residues that are found in all SECIS elements are in red boldface. Residues that are conserved but not universal are shown in blue boldface.
Fig. 2
Fig. 2
Amino acid alignment of canonical and Sec-specific elongation factors. Similar amino acids are in blue, highly conserved and identical residues in red. Asterisks denote the contacts between yeast eEF1A and F163 in eEF1Bα as described in Section 3 in the text. The alignment was generated by Multalin (Corpet, 1988).
Fig. 3
Fig. 3
Crystal structure of the eEF1A/eEF1Bα/GDPNP complex as reported in Andersen et al. (2000). Modeling was performed with Protein Explorer (Eric Martz) using PDB coordinates 1G7C. eEF1A is in blue, eEF1Ba is in magenta, and regions of eEF1A that are deleted in eEFSec are in red. The two amino acids flanking an insertion in eEFSec are in brown.
Fig. 4
Fig. 4
A model of Sec incorporation. We propose that SBP2 binds as at least a dimer simultaneously to the ribosome and the SECIS element and thus may prevent release factor access. In addition, SBP2 may play an active role in delivering the eEFSec/Sec-tRNA complex to the ribosomal A site.

Similar articles

See all similar articles

Cited by 27 articles

See all "Cited by" articles
Feedback