de.mpg.escidoc.pubman.appbase.FacesBean
English
 
Help Guide Disclaimer Contact us Login
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Deacylated tRNA is released from the E site upon A site occupation but before GTP is hydrolyzed by EF-Tu

MPS-Authors

Dinos,  George
Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons50642

Wilson,  Daniel N.
Dept. of Vertebrate Genomics (Head: Hans Lehrach), Max Planck Institute for Molecular Genetics, Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons50444

Nierhaus,  Knud H.
Ribosomes, Max Planck Institute for Molecular Genetics, Max Planck Society;

Locator
There are no locators available
Fulltext (public)
There are no public fulltexts available
Supplementary Material (public)
There is no public supplementary material available
Citation

Dinos, G., Kalpaxis, D. L., Wilson, D. N., & Nierhaus, K. H. (2005). Deacylated tRNA is released from the E site upon A site occupation but before GTP is hydrolyzed by EF-Tu. Nucleic Acids Research (London), 33(16), 5291-5296. doi:10.1093/nar/gki833.


Cite as: http://hdl.handle.net/11858/00-001M-0000-0010-858F-9
Abstract
The presence or absence of deacylated tRNA at the E site sharply influences the activation energy required for binding of a ternary complex to the ribosomal A site indicating the different conformations that the E-tRNA imparts on the ribosome. Here we address two questions: (i) whether or not peptidyltransferase—the essential catalytic activity of the large ribosomal subunit—also depends on the occupancy state of the E site and (ii) at what stage the E-tRNA is released during an elongation cycle. Kinetics of the puromycin reaction on various functional states of the ribosome indicate that the A-site substrate of the peptidyltransferase center, puromycin, requires the same activation energy for peptide-bond formation under all conditions tested. We further demonstrate that deacylated tRNA is released from the E site by binding a ternary complex aminoacyl-tRNA•EF-Tu•GDPNP to the A site. This observation indicates that the E-tRNA is released after the decoding step but before both GTP hydrolysis by EF-Tu and accommodation of the A-tRNA. Collectively these results reveal that the reciprocal linkage between the E and A sites affects the decoding center on the 30S subunit, but does not influence the rate of peptide-bond formation at the active center of the 50S subunit.