NMR Investigations of Subunit c of the ATP Synthase from Propionigenium modestum
in Chloroform/methanol/water (4:4:1)

ion-binding subunit of the Na+-translocating F1F0 ATP synthase from Propionigenium modestum

NMR investigations of subunit c of the ATP synthase from Propionigenium modestum in chloroform/methanol/water (4 : 4 : 1).

The structure of the Na+, Li+ or H+-binding c subunit of the ATP synthase from
Propionigenium modestum was studied by NMR. Subunit c in dodecylsulphate
micelles consists of four alpha-helical segments, I-IV, that are connected by
short linker peptides with non-regular secondary structures. We propose that
helices I (V4-I26) and IV (I69-V85) are membrane-spanning structures, and that
helices II and III and the intervening hydrophilic loop are located in the
cytoplasm. The Na+-binding residues Q32, E65 and S66 are located in the I-->II
and III-->IV helix connections, probably near the membrane surface on the
cytoplasmic side.

Matthey U, Kaim G, Braun D, Wuthrich K, Dimroth P.
NMR studies of subunit c of the ATP synthase from Propionigenium modestum
in dodecylsulphate micelles.
Eur J Biochem. 1999 Apr;261(2):459-67.

NMR studies of subunit c of the ATP synthase from Propionigenium modestum in dodecylsulphate micelles.

F1F0 ATP synthases use a transmembrane proton gradient to drive the synthesis of
cellular ATP. The structure of the cytosolic F1 portion of the enzyme and the
basic mechanism of ATP hydrolysis by F1 are now well established, but how
proton translocation through the transmembrane F0 portion drives these
catalytic changes is less clear. Here we describe the structural changes in the
proton-translocating F0 subunit c that are induced by deprotonating the
specific aspartic acid involved in proton transport. Conformational changes
between the protonated and deprotonated forms of subunit c provide the
structural basis for an explicit mechanism to explain coupling of proton
translocation by F0 to the rotation of subunits within the core of F1. Rotation
of these subunits within F1 causes the catalytic conformational changes in the
active sites of F1 that result in ATP synthesis.

Rastogi VK, Girvin ME.
Structural changes linked to proton translocation by subunit c of the ATP synthase.
Nature. 1999 Nov 18;402(6759):263-8.

Structural changes linked to proton translocation by subunit c of the ATP synthase.

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.

Girvin ME, Rastogi VK, Abildgaard F, Markley JL, Fillingame RH.
Solution structure of the transmembrane H+-transporting subunit c of the F1F0 ATP synthase.
Biochemistry. 1998 Jun 23;37(25):8817-24.

Solution structure of the transmembrane H+-transporting subunit c of the F1F0 ATP synthase.

ATPase subunit c [Propionigenium modestum]

unnamed protein product [Propionigenium modestum]

ATPase c subunit [Propionigenium modestum]

sodium dependent ATPase F1 subunit c [Propionigenium modestum, Peptide, 89 aa]

RecName: Full=ATP synthase subunit c, sodium ion specific; AltName: Full=ATP synthase F(0) sector subunit c; AltName: Full=F-ty

Overexpression in Escherichia coli PEF42(DE3).

German collection of microorganisms (DSM).

The protein was meassured in dodecyl sulfate micelle system.