Format

Send to

Choose Destination
See comment in PubMed Commons below
Proc Natl Acad Sci U S A. 2008 Oct 14;105(41):15702-7. doi: 10.1073/pnas.0804842105. Epub 2008 Oct 7.

Molecular code for protein insertion in the endoplasmic reticulum membrane is similar for N(in)-C(out) and N(out)-C(in) transmembrane helices.

Author information

1
Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden.

Abstract

Transmembrane alpha-helices in integral membrane proteins can have two orientations in the membrane: N(in)-C(out) or N(out)-C(in). Previous studies of model N(out)-C(in) transmembrane segment have led to a detailed, quantitative picture of the "molecular code" that relates amino acid sequence to membrane insertion efficiency in vivo [Hessa T, et al. (2007) Molecular code for transmembrane helix recognition by the Sec61 translocon. Nature 450:1026-1030], but whether the same code applies also to N(in)-C(out) transmembrane helices is unknown. Here, we show that the contributions of individual amino acids to the overall efficiency of membrane insertion are similar for the two kinds of helices and that the threshold hydrophobicity for membrane insertion can be up to approximately 1 kcal/mol lower for N(in)-C(out) compared with N(out)-C(in) transmembrane helices, depending on the neighboring helices.

PMID:
18840693
PMCID:
PMC2572976
DOI:
10.1073/pnas.0804842105
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Support Center