Mikel Valle1, 7, Andrey Zavialov2, Wen Li3, Scott M Stagg4, Jayati Sengupta3, Rikke C Nielsen5, Poul Nissen5, Stephen C Harvey4, Måns Ehrenberg2
& Joachim Frank1, 61
Howard Hughes Medical Institute, Health Research, Inc. at the Wadsworth Center, Empire State Plaza, Albany, New York 12201-0509, USA.
2
Department of Cell and Molecular Biology, Biomedical Center, Box 596, S-751 24 Uppsala, Sweden.
3
Wadsworth Center, Empire State Plaza, Albany, New York 12201-0509, USA.
4
School of Biology, Georgia Institute of Technology, 310 Ferst Drive, Atlanta, Georgia 30332, USA.
5
Department of Molecular Biology, University of Aarhus, Gustav Wieds vej 10C, DK-8000 Aarhus C, Denmark.
6
Department of Biomedical Sciences, State University of New York at Albany, Empire State Plaza, Albany, New York 12201-0509, USA.
7
Present address: Centro Nacional de Biotecnología, CSIC, Universidad Autónoma de Madrid, Cantoblanco 28049, Madrid, Spain.
Correspondence should be addressed to Joachim Frank joachim@wadsworth.org
9 Å, showing that during the incorporation of the aa-tRNA into the 70S ribosome of Escherichia coli, the flexibility of aa-tRNA allows the initial codon recognition and its accommodation into the ribosomal A site. In addition, a conformational change observed in the GTPase-associated center (GAC) of the ribosomal 50S subunit may provide the mechanism by which the ribosome promotes a relative movement of the aa-tRNA with respect to EF-Tu. This relative rearrangement seems to facilitate codon recognition by the incoming aa-tRNA, and to provide the codon-anticodon recognition-dependent signal for the GTPase activity of EF-Tu. From these new findings we propose a mechanism that can explain the sequence of events during the decoding of mRNA on the ribosome.
