TY  - JOUR
AU  - Fischer, Niels
AU  - Neumann, Piotr
AU  - Bock, Lars V.
AU  - Maracci, Cristina
AU  - Wang, Zhe
AU  - Paleskava, Alena
AU  - Konevega, Andrey L.
AU  - Schröder, Gunnar
AU  - Helmut, Grubmüller
AU  - Ficner, Ralf
AU  - Rodnina, Marina V.
AU  - Stark, Holger
TI  - The pathway to GTPase activation of elongation factor SelB on the ribosome
JO  - Nature 
VL  - 540
SN  - 0028-0836
CY  - London [u.a.]
PB  - Nature Publ. Group
M1  - FZJ-2017-01260
SP  - 80–85
PY  - 2016
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000388916600051
C6  - pmid:27842381
DO  - DOI:10.1038/nature20560
UR  - https://juser.fz-juelich.de/record/827054
ER  -