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Cryo‐EM structure of MsbA in saposin‐lipid nanoparticles (Salipro) provides insights into nucleotide coordination
Author(s) -
Kehlenbeck DominiqueMaurice,
Traore Daouda A.K.,
Josts Inokentijs,
Sander Simon,
Moulin Martine,
Haertlein Michael,
Prevost Sylvain,
Forsyth V. Trevor,
Tidow Henning
Publication year - 2022
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.16327
Subject(s) - cryo electron microscopy , atp binding cassette transporter , flippase , vanadate , nucleotide , bacterial outer membrane , chemistry , structural biology , biophysics , lipid ii , inner membrane , biochemistry , biology , transporter , membrane , escherichia coli , gene , phospholipid , phosphatidylserine , peptidoglycan
The ATP‐binding cassette transporter MsbA is a lipid flippase, translocating lipid A, glycolipids, and lipopolysaccharides from the inner to the outer leaflet of the inner membrane of Gram‐negative bacteria. It has been used as a model system for time‐resolved structural studies as several MsbA structures in different states and reconstitution systems (detergent/nanodiscs/peptidiscs) are available. However, due to the limited resolution of the available structures, detailed structural information on the bound nucleotides has remained elusive. Here, we have reconstituted MsbA in saposin A–lipoprotein nanoparticles (Salipro) and determined the structure of ADP‐vanadate‐bound MsbA by single‐particle cryo‐electron microscopy to 3.5 Å resolution. This procedure has resulted in significantly improved resolution and enabled us to model all side chains and visualise detailed ADP‐vanadate interactions in the nucleotide‐binding domains. The approach may be applicable to other dynamic membrane proteins.