T. Hessa et al., ?Recognition of transmembrane helices by the endoplasmic reticulum translocon,? Nature, 433:377?81, 2005. (Cited in 88 papers)
Gunnar von Heijne at Stockholm University and colleagues systematically altered the sequence of a transmembrane helix segment to understand how the translocon protein complex determines the segment?s placement in a lipid membrane. ?We figured out how to speak to the translocon, and we?re learning what its code is for inserting transmembrane proteins,? says co-author Stephen White from the University of California, Irvine.
It was easy to imagine that a peptide?s interaction with the translocon determined a segment?s location, says von Heijne. But this paper provided evidence that the protein?s interactions with the lipid bilayer are directing the translocon.
Von Heijne has tested several hundred additional polypeptides in various systems, such as Escherichia coli...
|Free energy range||Peptides||Favored position|
|<0 kcal/mol||Isoleucine-Valine||Hydrocarbon core|
|-0 kcal/mol||Cysteine-Alanine||Interfacial region|
|>0 kcal/mol||Charged and polar residues||Aqueous layer|