Change search
ReferencesLink to record
Permanent link

Direct link
Differential repositioning of the second transmembrane helices from E. coli Tar and EnvZ upon moving the flanking aromatic residues
Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
2015 (English)In: Biochimica et Biophysica Acta - Biomembranes, ISSN 0005-2736, E-ISSN 1879-2642, Vol. 1848, no 2, 615-621 p.Article in journal (Refereed) Published
Abstract [en]

Aromatic tuning, i.e. repositioning aromatic residues found at the cytoplasmic end of transmembrane (TM) domains within bacterial receptors, has been previously shown to modulate signal output from the aspartate chemoreceptor (Tar) and the major osmosensor EnvZ of Escherichia coli. In the case of Tar, changes in signal output consistent with the vertical position of the native Trp-Tyr aromatic tandem within TM2 were observed. In contrast, within EnvZ, where a Trp-Leu-Phe aromatic triplet was repositioned, the surface that the triplet resided upon was the major determinant governing signal output. However, these studies failed to determine whether moving the aromatic residues was sufficient to physically reposition the TM helix within a membrane. Recent coarse-grained molecular dynamics (CG-MD) simulations predicted displacement of Tar TM2 upon moving the aromatic residues at the cytoplasmic end of the helix. Here, we demonstrate that repositioning the Trp-Tyr tandem within Tar TM2 displaces the C-terminal boundary of the helix relative to the membrane. In a similar analysis of EnvZ, an abrupt initial displacement of TM2 was observed but no subsequent movement was seen, suggesting that the vertical position of TM2 is not governed by the location of the Trp-Leu-Phe triplet. Our results also provide another set of experimental data, i.e. the resistance of EnvZ TM2 to being displaced upon aromatic tuning, which could be useful for subsequent refinement of the initial CG-MD simulations. Finally, we discuss the limitations of these methodologies, how moving flanking aromatic residues might impact steady-state signal output and the potential to employ aromatic tuning in other bacterial membrane-spanning receptors.

Place, publisher, year, edition, pages
2015. Vol. 1848, no 2, 615-621 p.
Keyword [en]
Aromatic tuning, Hydrophobic-polar membrane interface, Interfacial anchoring, Transmembrane helices, Glycosylation mapping
National Category
Biological Sciences
URN: urn:nbn:se:su:diva-114347DOI: 10.1016/j.bbamem.2014.11.017ISI: 000348687500027PubMedID: 25445668OAI: diva2:793697


Available from: 2015-03-09 Created: 2015-03-02 Last updated: 2015-03-09Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textPubMed

Search in DiVA

By author/editor
Botelho, Salome C.von Heijne, Gunnar
By organisation
Department of Biochemistry and Biophysics
In the same journal
Biochimica et Biophysica Acta - Biomembranes
Biological Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 38 hits
ReferencesLink to record
Permanent link

Direct link