Interaction of nascent chains with the ribosomal tunnel proteins Rpl4, Rpl17, and Rpl39 of Saccharomyces cerevisiae.

ABSTRACT: As translation proceeds, nascent polypeptides pass through an exit tunnel that traverses the large ribosomal subunit. Three ribosomal proteins, termed Rpl4, Rpl17, and Rpl39 expose domains to the interior of the exit tunnel of eukaryotic ribosomes. Here we generated ribosome-bound nascent chains in a homologous yeast translation system to analyze contacts between the tunnel proteins and nascent chains. As model proteins we employed Dap2, which contains a hydrophobic signal anchor (SA) segment, and the chimera Dap2α, in which the SA was replaced with a hydrophilic segment, with the propensity to form an α-helix. Employing a newly developed FLAG exposure assay, we find that the nascent SA segment but not the hydrophilic segment adopted a stable, α-helical structure within the tunnel when the

SUBMITTER: Zhang Y 

PROVIDER: S-EPMC3837115 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature