Quantitative Analysis of SecYEG-Mediated Insertion of Transmembrane alpha-Helices into the Bacterial Inner Membrane
2013 (English)In: Journal of Molecular Biology, ISSN 0022-2836, E-ISSN 1089-8638, Vol. 425, no 15, 2813-2822 p.Article in journal (Refereed) Published
Most integral membrane proteins, both in prokaryotic and eukaryotic cells, are co-translationally inserted into the membrane via Sec-type translocons: the SecYEG complex in prokaryotes and the Sec61 complex in eukaryotes. The contributions of individual amino acids to the overall free energy of membrane insertion of single transmembrane alpha-helices have been measured for Sec61-mediated insertion into the endoplasmic reticulum (ER) membrane (Nature 450:1026-1030) but have not been systematically determined for SecYEG-mediated insertion into the bacterial inner membrane. We now report such measurements, carried out in Escherichia coli. Overall, there is a good correlation between the results found for the mammalian ER and the E. coli inner membrane, but the hydrophobicity threshold for SecYEG-mediated insertion is distinctly lower than that for Sec61-mediated insertion.
Place, publisher, year, edition, pages
2013. Vol. 425, no 15, 2813-2822 p.
SecYEG, leader peptidase, membrane protein, transmembrane helix
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:su:diva-93567DOI: 10.1016/j.jmb.2013.04.025ISI: 000322296400015OAI: oai:DiVA.org:su-93567DiVA: diva2:647503