TOPCONS Friday, March 29 2024
Main Menu
New query
SCAMPI
OCTOPUS
ΔG-scale
ZPRED
PRO/PRODIV
Download
Help
ΔG-scale

Abstract

Transmembrane alpha-helices in integral membrane proteins are recognized co-translationally and inserted into the membrane of the endoplasmic reticulum by the Sec61 translocon. A full quantitative description of this phenomenon, linking amino acid sequence to membrane insertion efficiency, is still lacking. Here, using in vitro translation of a model protein in the presence of dog pancreas rough microsomes to analyse a large number of systematically designed hydrophobic segments, we present a quantitative analysis of the position-dependent contribution of all 20 amino acids to membrane insertion efficiency, as well as of the effects of transmembrane segment length and flanking amino acids. The emerging picture of translocon-mediated transmembrane helix assembly is simple, with the critical sequence characteristics mirroring the physical properties of the lipid bilayer.

[PubMed]
 
 
© 2008 Stockholm University, Stockholm Bioinformatics Center