Dobosz-Bartoszek_Malgorzata.pdf (37.5 MB)
Structural and Biochemical Studies of the Human Selenocysteine tRNA-Specific Elongation Factor eEFSec
thesis
posted on 2016-10-19, 00:00 authored by Malgorzata M. Dobosz-BartoszekSelenocysteine is the only proteinogenic amino acid encoded by a recoded in-frame UGA codon that does not operate as the canonical opal stop codon. A specialized translation elongation factor, eEFSec in eukaryotes and SelB in prokaryotes, promotes selenocysteine incorporation into selenoproteins by a still poorly understood mechanism. My structural and biochemical results reveal that four domains of human eEFSec fold into a chalice-like structure that has similar binding affinities for GDP, GTP and other guanine nucleotides. Surprisingly, unlike in eEF1A and EF-Tu, the guanine nucleotide exchange does not cause a major conformational change in domain 1 of eEFSec, but instead induces a swing of domain 4. I propose that eEFSec employs a non-canonical mechanism involving the distinct C-terminal domain 4 for the release of the selenocysteinyl-tRNA during decoding on the ribosome.
History
Advisor
Simonovic, MiljanDepartment
Biochemistry and Molecular GeneticsDegree Grantor
University of Illinois at ChicagoDegree Level
- Doctoral
Committee Member
Caffrey, Michael Colley, Karen Lavie, Arnon Mankin, Alexander Volz, KarlSubmitted date
2016-08Language
- en
Issue date
2016-10-19Usage metrics
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