James Gumbart, Leonardo G. Trabuco, Eduard Schreiner, Elizabeth Villa, and
Klaus Schulten.
Regulation of the protein-conducting channel by a bound ribosome.
Structure, 17:1453-1464, 2009.
(PMC: 2778611)
GUMB2009
During protein synthesis, it is often necessary for the ribosome to form a complex with a membrane-bound channel, the SecY/Sec61 complex, in order to translocate nascent proteins across a cellular membrane. Structural data on the ribosome-channel complex are currently limited to low-resolution cryo-electron microscopy maps, including most recently one showing a bacterial ribosome bound to a monomeric SecY complex. Using that map along with molecular dynamics flexible fitting, we have modeled and simulated an atomic-resolution structure of the ribosome-channel complex. We characterized the sites of interaction within the complex and determined the effects of ribosome binding on the SecY channel. We also constructed a model of a ribosome in complex with a SecY dimer, finding that in simulation the dimer enhances ribosome binding and destabilizes a channel-blocking plug, preparing the channel to receive the nascent polypeptide. The study involved 2.7-million-atom simulations over altogether nearly 50 ns.
Download Full Text
The manuscripts available on our site are provided for your personal
use only and may not be retransmitted or redistributed without written
permissions from the paper's publisher and author. You may not upload any
of this site's material to any public server, on-line service, network, or
bulletin board without prior written permission from the publisher and
author. You may not make copies for any commercial purpose. Reproduction
or storage of materials retrieved from this web site is subject to the
U.S. Copyright Act of 1976, Title 17 U.S.C.