Format

Send to

Choose Destination
Nat Chem. 2015 Mar;7(3):255-62. doi: 10.1038/nchem.2172. Epub 2015 Feb 2.

A subset of annular lipids is linked to the flippase activity of an ABC transporter.

Author information

1
Department of Chemistry, University of Oxford, Oxford OX1 3QZ, UK.
2
Institute of Biochemistry, Biocenter, Goethe-University Frankfurt, Frankfurt 60438, Germany.
3
Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Frankfurt 60438, Germany.
4
1] Institute of Biochemistry, Biocenter, Goethe-University Frankfurt, Frankfurt 60438, Germany [2] Cluster of Excellence-Macromolecular Complexes, Goethe-University Frankfurt, Frankfurt 60438, Germany.

Abstract

Lipids are critical components of membranes that could affect the properties of membrane proteins, yet the precise compositions of lipids surrounding membrane-embedded protein complexes is often difficult to discern. Here we report that, for the heterodimeric ABC transporter TmrAB, the extent of delipidation can be controlled by timed exposure to detergent. We subsequently characterize the cohort of endogenous lipids that are extracted in contact with the membrane protein complex, and show that with prolonged delipidation the number of neutral lipids is reduced in favour of their negatively charged counterparts. We show that lipid A is retained by the transporter and that the extent of its binding decreases during the catalytic cycle, implying that lipid A release is linked to adenosine tri-phosphate hydrolysis. Together, these results enable us to propose that a subset of annular lipids is invariant in composition, with negatively charged lipids binding tightly to TmrAB, and imply a role for this exporter in glycolipid translocation.

Comment in

PMID:
25698336
DOI:
10.1038/nchem.2172
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Nature Publishing Group
Loading ...
Support Center