1A91

SUBUNIT C OF THE F1FO ATP SYNTHASE OF ESCHERICHIA COLI; NMR, 10 STRUCTURES

Summary for 1A91

• Entry DOI: 10.2210/pdb1a91/pdb
• Descriptor: F1FO ATPASE SUBUNIT C (1 entity in total)
• Functional Keywords: membrane protein, hydrogen ion transport
• Biological source: Escherichia coli
• Cellular location: Cell inner membrane; Multi-pass membrane protein: P68699
• Total number of polymer chains: 1
• Total formula weight: 8259.06

Authors

Girvin, M.E.,Rastogi, V.K.,Abildgaard, F.,Markley, J.L.,Fillingame, R.H. (deposition date: 1998-04-15, release date: 1998-07-01, Last modification date: 2024-05-22)

Primary citation

Girvin, M.E.,Rastogi, V.K.,Abildgaard, F.,Markley, J.L.,Fillingame, R.H.
Solution structure of the transmembrane H+-transporting subunit c of the F1F0 ATP synthase.
Biochemistry, 37:8817-8824, 1998

PubMed Abstract: Subunit c is the H+-translocating component of the F1F0 ATP synthase complex. H+ transport is coupled to conformational changes that ultimately lead to ATP synthesis by the enzyme. The properties of the monomeric subunit in a single-phase solution of chloroform-methanol-water (4:4:1) have been shown to mimic those of the protein in the native complex. Triple resonance NMR experiments were used to determine the complete structure of monomeric subunit c in this solvent mixture. The structure of the protein was defined by >2000 interproton distances, 64 (3)JN alpha, and 43 hydrogen-bonding NMR-derived restraints. The root mean squared deviation for the backbone atoms of the two transmembrane helices was 0.63 A. The protein folds as a hairpin of two antiparallel helical segments, connected by a short structured loop. The conserved Arg41-Gln42-Pro43 form the top of this loop. The essential H+-transporting Asp61 residue is located at a slight break in the middle of the C-terminal helix, just prior to Pro64. The C-terminal helix changes direction by 30 +/- 5 degrees at the conserved Pro64. In its protonated form, the Asp61 lies in a cavity created by the absence of side chains at Gly23 and Gly27 in the N-terminal helix. The shape and charge distribution of the molecular surface of the monomeric protein suggest a packing arrangement for the oligomeric protein in the F0 complex, with the front face of one monomer packing favorably against the back face of a second monomer. The packing suggests that the proton (cation) binding site lies between packed pairs of adjacent subunit c.

PubMed: 9636021
DOI: 10.1021/bi980511m

Experimental method

SOLUTION NMR