Skip to main content
. 2005 Dec 27;63(1):73–81. doi: 10.1007/s00018-005-5402-y

Figure 3.

Figure 3

Contrasting models for Sec incorporation. (A) A common model for Sec incorporation. An SBP2-bound SECIS element recruits the eEFSec/Sec-tRNA[Ser]Sec complex. After association with the ribosome, SBP2 is exchanged for rpL30 resulting from a kinked SECIS element. This conformational change in the SECIS element is hypothesized to trigger the release of the Sec-tRNA[Ser]Sec and GTP hydrolysis. (B) A model of Sec incorporation based on the topics discussed in this review. SBP2 is pre-bound to the ribosome. Upon arrival at a UGA codon, ribosome stalling allows for a distant SECIS element to find and interact with SBP2. Movement of SBP2 may trigger conformational changes in the ribosomal A-site that favor the binding of eEFSec/Sec-tRNA[Ser]Sec and the subsequent insertion of Sec. After incorporation, rpL30 may function to displace SBP2 off the SECIS element and back to its original position on the ribosome.