Premium
Importance of Hydrophobic Bulk at the Rotor‐Stator Interface of E. coli ATP Synthase
Author(s) -
Dodd Michaela,
Pressley Benjamin,
Steed Ryan
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.794.3
Subject(s) - atp synthase , chemiosmosis , electrochemical gradient , steric effects , atpase , adenosine triphosphate , chemistry , protein subunit , biophysics , stator , v atpase , stereochemistry , biochemistry , membrane , enzyme , biology , physics , gene , quantum mechanics
As the primary producer of adenosine triphosphate (ATP), the chemical energy currency of cells, F 1 F o ATP synthase is essential for life. Using the H + electrochemical gradient, the membrane‐embedded F o complex generates torque on the cytoplasmic F 1 complex, which synthesizes ATP from ADP and phosphate. While much is known about the mechanism of ATP synthesis, aspects of F o functionality, including the roles of interactions between subunit a (stator) and the c 10 ring (rotor), remain unresolved. In E. coli , Phe54 and Ile55 on subunit c have been found in a previous study to be important for H + movement through F o during ATP‐driven H + pumping. We show here that c F54C and c I55C mutations cannot pump or passively translocate protons through F o . ATP‐driven H + pumping activity was partially restored by systematically adding steric bulk to Cys54 through chemical modifications with methanethiosulfonate derivatives of increasing size; however, similar restoration did not occur for Cys55. Additionally, we used site‐directed mutagenesis to replace Phe54 or Ile55 with hydrophobic amino acids of various size, all of which supported H + pumping activity. While the chemical modification of Cys54 suggested that hydrophobic bulk at this position is important for H + pumping, the chemical properties required at these positions remain unclear. Support or Funding Information Supported by the North Carolina GlaxoSmithKline Foundation and the University of North Carolina Asheville Undergraduate Research Program This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .