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Updated: Jul 19, 2026

Transmembrane Domain Oligomerization Propensity determined by ToxR Assay
Published on: May 26, 2011
Asn- and Asp-mediated interactions between transmembrane helices during translocon-mediated membrane protein assembly
Nadja M Meindl-Beinker1, Carolina Lundin, Ingmarie Nilsson
1Department of Biochemistry and Biophysics, Center for Biomembrane Research, Stockholm University, SE-106 91 Stockholm, Sweden.
Abstract:
Inter-helix hydrogen bonding involving asparagine (Asn, N), glutamine (Gln, Q), aspartic acid (Asp, D) or glutamic acid (Glu, E) can drive efficient di- or trimerization of transmembrane helices in detergent micelles and lipid bilayers. Likewise, Asn-Asn and Asp-Asp pairs can promote the formation of helical hairpins during translocon-mediated membrane protein assembly in the endoplasmic reticulum. By in vitro translation of model integral membrane protein constructs in the presence of rough microsomes, we show that Asn- or Asp-mediated interactions with a neighbouring transmembrane helix can enhance the membrane insertion efficiency of a marginally hydrophobic transmembrane segment. Our observations suggest that inter-helix hydrogen bonds can form during Sec61 translocon-assisted insertion and thus could be important for membrane protein assembly.
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