Project Details
Projekt
Mechanism of selenocysteine incorporation on the ribosome
Applicant
Dr. Kirill Gromadski
Subject Area
Biochemistry
Term
from 2005 to 2008
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 20967925
The insertion of selenocysteine into proteins in bacteria requires a UGA codon in the open reading frame of mRNA, a specific mRNA hairpin structure (SECIS element), tRNASec, and a specialized elongation factor termed SelB. The molecular mechanism of SelB function on the ribosome and the sequence of events during selenocysteine incorporation are not known so far. The present project aims at understanding the molecular mechanisms of setenocysteine incorporation in bacteria by using biochemical and biophysical in vitro techniques. We plan to establish the experimental system to study the interactions between SelB, GTP, Sec-tRNASec and the ribosome programmed with mRNA containing a SECIS element using rapid kinetics and biophysical techniques. The mechanism of GTPase activation of SelB in the ternary complex and its regulation by the mRNA recognition elements, i.e. UGA codon and SECIS, will be investigated. Reaction intermediates will be identified and the kinetics of the transitions between the intermediates will be determined. The results are expected to shed light on the molecular pathway of selenocysteine incorporation and on the mechanisms of substrate recognition and selection during translation in general.
DFG Programme
Research Fellowships
