Cotranslational folding of membrane proteins probed by arrest-peptide-mediated force measurements
2013 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 110, no 36, 14640-14645 p.Article in journal (Refereed) Published
Polytopic membrane proteins are inserted cotranslationally into target membranes by ribosome-translocon complexes. It is, however, unclear when during the insertion process specific interactions between the transmembrane helices start to form. Here, we use a recently developed in vivo technique to measure pulling forces acting on transmembrane helices during their cotranslational insertion into the inner membrane of Escherichia coli to study the earliest steps of tertiary folding of five polytopic membrane proteins. We find that interactions between residues in a C-terminally located transmembrane helix and in more N-terminally located helices can be detected already at the point when the C-terminal helix partitions from the translocon into the membrane. Our findings pinpoint the earliest steps of tertiary structure formation and open up possibilities to study the cotranslational folding of polytopic membrane proteins.
Place, publisher, year, edition, pages
2013. Vol. 110, no 36, 14640-14645 p.
protein folding, membrane insertion, helix-helix interactions
Natural Sciences Engineering and Technology
IdentifiersURN: urn:nbn:se:su:diva-94178DOI: 10.1073/pnas.1306787110ISI: 000323886200041OAI: oai:DiVA.org:su-94178DiVA: diva2:652613
European Research Council ERC-2008-AdG 232648; Swedish Foundation for Strategic Research; Swedish Research Council; Deutsche Forschungsgemeinschaft CY 74/1-1 2013-10-012013-09-302013-10-01Bibliographically approved