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Gonzalez RL Jr, Chu S, Puglisi JD RNA. 2007 Dec;13(12):2091-7.
Thiostrepton inhibition of tRNA delivery to the ribosome.
Department of Structural Biology, Stanford University School
of Medicine, Stanford, California 94305-5126, USA.
Ribosome-stimulated hydrolysis of guanosine-5'-triphosphate (GTP)
by guanosine triphosphatase (GTPase) translation factors drives
protein synthesis by the ribosome. Allosteric coupling of GTP
hydrolysis by elongation factor Tu (EF-Tu) at the ribosomal
GTPase center to messenger RNA (mRNA) codon:aminoacyl-transfer
RNA (aa-tRNA) anticodon recognition at the ribosomal decoding
site is essential for accurate and rapid aa-tRNA selection. Here
we use single-molecule methods to investigate the mechanism of
action of the antibiotic thiostrepton and show that the GTPase
center of the ribosome has at least two discrete functions
during aa-tRNA selection: binding of EF-Tu(GTP) and stimulation
of GTP hydrolysis by the factor. We separate these two functions
of the GTPase center and assign each to distinct, conserved
structural regions of the ribosome. The data provide a specific
model for the coupling between the decoding site and the GTPase
center during aa-tRNA selection as well as a general mechanistic
model for ribosome-stimulated GTP hydrolysis by GTPase
translation factors.
PMID: 17951333 |
