TCB Publications - Paper Request

Birgit Seidelt, C. Axel Innis, Daniel N. Wilson, Marco Gartmann, Jean-Paul Armache, Elizabeth Villa, Leonardo G. Trabuco, Thomas Becker, Thorsten Mielke, Klaus Schulten, Thomas A. Steitz, and Roland Beckmann. Structural insight into nascent polypeptide chain-mediated translational stalling. Science, 326:1412-1415, 2009.

SEID2009 Expression of the Escherichia coli tryptophanase operon under inducing tryptophan concentrations is dependent upon ribosome stalling during translation of the upstream TnaC leader peptide. Interaction between the TnaC nascent chain and the ribosomal tunnel is thought to be critical for efficient stalling. We have determined a 5.8 $\AA$ resolution cryo-EM and single particle reconstruction of an E. coli 70S ribosome stalled during translation of the TnaC leader gene. The quality of the map allows the ordered TnaC nascent chain to be observed within the exit tunnel of the ribosome, making contacts with ribosomal components at distinct sites. At the peptidyltransferase center of the ribosome, the universally conserved A2602 and U2585 adopt conformations that are incompatible with co-habitation of the termination release factors. The TnaC interactions within the tunnel are suggested to produce structural changes that are relayed to inactivate the peptidyltransferase center. This study clearly indicates that individual nascent chains can adopt distinct conformations within the exit tunnel.



Request Paper

Full Name
Email Address
Institution
Type the number seven in the box