| First Author | Gonzalez-Flores JN | Year | 2012 |
| Journal | J Biol Chem | Volume | 287 |
| Issue | 46 | Pages | 38936-45 |
| PubMed ID | 22992746 | Mgi Jnum | J:192960 |
| Mgi Id | MGI:5467162 | Doi | 10.1074/jbc.M112.415463 |
| Citation | Gonzalez-Flores JN, et al. (2012) The selenocysteine-specific elongation factor contains a novel and multi-functional domain. J Biol Chem 287(46):38936-45 |
| abstractText | The selenocysteine (Sec)-specific eukaryotic elongation factor (eEFSec) delivers the aminoacylated selenocysteine-tRNA (Sec-tRNA(Sec)) to the ribosome and suppresses UGA codons that are upstream of Sec insertion sequence (SECIS) elements bound by SECIS-binding protein 2 (SBP2). Multiple studies have highlighted the importance of SBP2 forming a complex with the SECIS element, but it is not clear how this regulates eEFSec during Sec incorporation. Compared with the canonical elongation factor eEF1A, eEFSec has a unique C-terminal extension called Domain IV. To understand the role of Domain IV in Sec incorporation, we examined a series of mutant proteins for all of the known molecular functions for eEFSec: GTP hydrolysis, Sec-tRNA(Sec) binding, and SBP2/SECIS binding. In addition, wild-type and mutant versions of eEFSec were analyzed for Sec incorporation activity in a novel eEFSec-dependent translation extract. We have found that Domain IV is essential for both tRNA and SBP2 binding as well as regulating GTPase activity. We propose a model where the SBP2/SECIS complex activates eEFSec by directing functional interactions between Domain IV and the ribosome to promote Sec-tRNA(Sec) binding and accommodation into the ribosomal A-site. |
