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Molecular architecture of the N‐type ATP ase rotor ring from Burkholderia pseudomallei
Author(s) -
Schulz Sarah,
Wilkes Martin,
Mills Deryck J,
Kühlbrandt Werner,
Meier Thomas
Publication year - 2017
Publication title -
embo reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.584
H-Index - 184
eISSN - 1469-3178
pISSN - 1469-221X
DOI - 10.15252/embr.201643374
Subject(s) - burkholderia pseudomallei , atp synthase , bacteria , operon , biophysics , ring (chemistry) , chemistry , biochemistry , melioidosis , stereochemistry , biology , escherichia coli , gene , microbiology and biotechnology , genetics , organic chemistry
The genome of the highly infectious bacterium Burkholderia pseudomallei harbors an atp operon that encodes an N‐type rotary ATP ase, in addition to an operon for a regular F‐type rotary ATP ase. The molecular architecture of N‐type ATP ases is unknown and their biochemical properties and cellular functions are largely unexplored. We studied the B. pseudomallei N 1 N o ‐type ATP ase and investigated the structure and ion specificity of its membrane‐embedded c‐ring rotor by single‐particle electron cryo‐microscopy. Of several amphiphilic compounds tested for solubilizing the complex, the choice of the low‐density, low‐ CMC detergent LDAO was optimal in terms of map quality and resolution. The cryo EM map of the c‐ring at 6.1 Å resolution reveals a heptadecameric oligomer with a molecular mass of ~141 kD a. Biochemical measurements indicate that the c 17 ring is H + specific, demonstrating that the ATP ase is proton‐coupled. The c 17 ring stoichiometry results in a very high ion‐to‐ ATP ratio of 5.7. We propose that this N‐ ATP ase is a highly efficient proton pump that helps these melioidosis‐causing bacteria to survive in the hostile, acidic environment of phagosomes.