%0 Journal Article
%A Fischer, Niels
%A Neumann, Piotr
%A Bock, Lars V.
%A Maracci, Cristina
%A Wang, Zhe
%A Paleskava, Alena
%A Konevega, Andrey L.
%A Schröder, Gunnar
%A Helmut, Grubmüller
%A Ficner, Ralf
%A Rodnina, Marina V.
%A Stark, Holger
%T The pathway to GTPase activation of elongation factor SelB on the ribosome
%J Nature 
%V 540
%@ 0028-0836
%C London [u.a.]
%I Nature Publ. Group
%M FZJ-2017-01260
%P 80–85
%D 2016
%X In all domains of life, selenocysteine (Sec) is delivered to the ribosome by selenocysteine-specific tRNA (tRNASec) with the help of a specialized translation factor, SelB in bacteria. Sec-tRNASec recodes a UGA stop codon next to a downstream mRNA stem–loop. Here we present the structures of six intermediates on the pathway of UGA recoding in Escherichia coli by single-particle cryo-electron microscopy. The structures explain the specificity of Sec-tRNASec binding by SelB and show large-scale rearrangements of Sec-tRNASec. Upon initial binding of SelB–Sec-tRNASec to the ribosome and codon reading, the 30S subunit adopts an open conformation with Sec-tRNASec covering the sarcin–ricin loop (SRL) on the 50S subunit. Subsequent codon recognition results in a local closure of the decoding site, which moves Sec-tRNASec away from the SRL and triggers a global closure of the 30S subunit shoulder domain. As a consequence, SelB docks on the SRL, activating the GTPase of SelB. These results reveal how codon recognition triggers GTPase activation in translational GTPases.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000388916600051
%$ pmid:27842381
%R 10.1038/nature20560
%U https://juser.fz-juelich.de/record/827054