Browse
Submit Data
Databases
API
Help

Dataset Information

25 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

36 degrees step size of proton-driven c-ring rotation in FoF1-ATP synthase.

ABSTRACT: Synthesis of adenosine triphosphate ATP, the 'biological energy currency', is accomplished by F(o)F(1)-ATP synthase. In the plasma membrane of Escherichia coli, proton-driven rotation of a ring of 10 c subunits in the F(o) motor powers catalysis in the F(1) motor. Although F(1) uses 120 degrees stepping during ATP synthesis, models of F(o) predict either an incremental rotation of c subunits in 36 degrees steps or larger step sizes comprising several fast substeps. Using single-molecule fluorescence resonance energy transfer, we provide the first experimental determination of a 36 degrees sequential stepping mode of the c-ring during ATP synthesis.

SUBMITTER: Duser MG

PROVIDER: S-EPMC2750017 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

36 degrees step size of proton-driven c-ring rotation in FoF1-ATP synthase.

Düser Monika G MG Zarrabi Nawid N Cipriano Daniel J DJ Ernst Stefan S Glick Gary D GD Dunn Stanley D SD Börsch Michael M

The EMBO journal 20090730 18

Synthesis of adenosine triphosphate ATP, the 'biological energy currency', is accomplished by F(o)F(1)-ATP synthase. In the plasma membrane of Escherichia coli, proton-driven rotation of a ring of 10 c subunits in the F(o) motor powers catalysis in the F(1) motor. Although F(1) uses 120 degrees stepping during ATP synthesis, models of F(o) predict either an incremental rotation of c subunits in 36 degrees steps or larger step sizes comprising several fast substeps. Using single-molecule fluoresc ...[more]

PMID: 19644443

Similar Datasets

ATP-driven stepwise rotation of FoF1-ATP synthase.

Project description:FoF1-ATP synthase (FoF1) is a motor enzyme that couples ATP synthesis/hydrolysis with a transmembrane proton translocation. F1, a water-soluble ATPase portion of FoF1, rotates by repeating ATP-waiting dwell, 80 degrees substep rotation, catalytic dwell, and 40 degrees -substep rotation. Compared with F1, rotation of FoF1 has yet been poorly understood, and, here, we analyzed ATP-driven rotations of FoF1. Rotation was probed with an 80-nm bead attached to the ring of c subunits in the immobilized FoF1 and recorded with a submillisecond fast camera. The rotation rates at various ATP concentrations obeyed the curve defined by a Km of approximately 30 microM and a Vmax of approximately 350 revolutions per second (at 37 degrees C). At low ATP, ATP-waiting dwell was seen and the kon-ATP was estimated to be 3.6 x 10(7) M(-1) x s(-1). At high ATP, fast, poorly defined stepwise motions were observed that probably reflect the catalytic dwells. When a slowly hydrolyzable substrate, adenosine 5'-[gamma-thio]triphosphate, was used, the catalytic dwells consisting of two events were seen more clearly at the angular position of approximately 80 degrees . The rotational behavior of FoF1 resembles that of F1. This finding indicates that "friction" in Fo motor is negligible during the ATP-driven rotation. Tributyltin chloride, a specific inhibitor of proton translocation, slowed the rotation rate by 96%. However, dwells at clearly defined angular positions were not observed under these conditions, indicating that inhibition by tributyltin chloride is complex.

| S-EPMC545493 | biostudies-literature

Mechanism of proton-powered c-ring rotation in a mitochondrial ATP synthase.

Project description:Proton-powered c-ring rotation in mitochondrial ATP synthase is crucial to convert the transmembrane protonmotive force into torque to drive the synthesis of adenosine triphosphate (ATP). Capitalizing on recent cryo-EM structures, we aim at a structural and energetic understanding of how functional directional rotation is achieved. We performed multi-microsecond atomistic simulations to determine the free energy profiles along the c-ring rotation angle before and after the arrival of a new proton. Our results reveal that rotation proceeds by dynamic sliding of the ring over the a-subunit surface, during which interactions with conserved polar residues stabilize distinct intermediates. Ordered water chains line up for a Grotthuss-type proton transfer in one of these intermediates. After proton transfer, a high barrier prevents backward rotation and an overall drop in free energy favors forward rotation, ensuring the directionality of c-ring rotation required for the thermodynamically disfavored ATP synthesis. The essential arginine of the a-subunit stabilizes the rotated configuration through a salt bridge with the c-ring. Overall, we describe a complete mechanism for the rotation step of the ATP synthase rotor, thereby illuminating a process critical to all life at atomic resolution.

| S-EPMC10945847 | biostudies-literature

Fo-driven Rotation in the ATP Synthase Direction against the Force of F1 ATPase in the FoF1 ATP Synthase.

Project description:Living organisms rely on the FoF1 ATP synthase to maintain the non-equilibrium chemical gradient of ATP to ADP and phosphate that provides the primary energy source for cellular processes. How the Fo motor uses a transmembrane electrochemical ion gradient to create clockwise torque that overcomes F1 ATPase-driven counterclockwise torque at high ATP is a major unresolved question. Using single FoF1 molecules embedded in lipid bilayer nanodiscs, we now report the observation of Fo-dependent rotation of the c10 ring in the ATP synthase (clockwise) direction against the counterclockwise force of ATPase-driven rotation that occurs upon formation of a leash with Fo stator subunit a. Mutational studies indicate that the leash is important for ATP synthase activity and support a mechanism in which residues aGlu-196 and cArg-50 participate in the cytoplasmic proton half-channel to promote leash formation.

| S-EPMC4409238 | biostudies-literature

Rotary catalysis of FoF1-ATP synthase.

Project description:The synthesis of ATP, the key reaction of biological energy metabolism, is accomplished by the rotary motor protein; FoF1-ATP synthase (FoF1). In vivo, FoF1, located on the cell membrane, carries out ATP synthesis by using the proton motive force. This heterologous energy conversion is supposed to be mediated by the mechanical rotation of FoF1; however, it still remained unclear. Recently, we developed the novel experimental setup to reproduce the proton motive force in vitro and succeeded in directly observing the proton-driven rotation of FoF1. In this review, we describe the interesting working principles determined so far for FoF1 and then introduce results from our recent study.

| S-EPMC4629669 | biostudies-literature

Elasticity, friction, and pathway of γ-subunit rotation in FoF1-ATP synthase.

Project description:We combine molecular simulations and mechanical modeling to explore the mechanism of energy conversion in the coupled rotary motors of FoF1-ATP synthase. A torsional viscoelastic model with frictional dissipation quantitatively reproduces the dynamics and energetics seen in atomistic molecular dynamics simulations of torque-driven γ-subunit rotation in the F1-ATPase rotary motor. The torsional elastic coefficients determined from the simulations agree with results from independent single-molecule experiments probing different segments of the γ-subunit, which resolves a long-lasting controversy. At steady rotational speeds of ∼ 1 kHz corresponding to experimental turnover, the calculated frictional dissipation of less than k(B)T per rotation is consistent with the high thermodynamic efficiency of the fully reversible motor. Without load, the maximum rotational speed during transitions between dwells is reached at ∼ 1 MHz. Energetic constraints dictate a unique pathway for the coupled rotations of the Fo and F1 rotary motors in ATP synthase, and explain the need for the finer stepping of the F1 motor in the mammalian system, as seen in recent experiments. Compensating for incommensurate eightfold and threefold rotational symmetries in Fo and F1, respectively, a significant fraction of the external mechanical work is transiently stored as elastic energy in the γ-subunit. The general framework developed here should be applicable to other molecular machines.

| S-EPMC4553772 | biostudies-other

Direct observation of stepped proteolipid ring rotation in E. coli F?F?-ATP synthase.

Project description:Although single-molecule experiments have provided mechanistic insight for several molecular motors, these approaches have proved difficult for membrane bound molecular motors like the F?F?-ATP synthase, in which proton transport across a membrane is used to synthesize ATP. Resolution of smaller steps in F? has been particularly hampered by signal-to-noise and time resolution. Here, we show the presence of a transient dwell between F? subunits a and c by improving the time resolution to 10 ?s at unprecedented S/N, and by using Escherichia coli F?F? embedded in lipid bilayer nanodiscs. The transient dwell interaction requires 163 ?s to form and 175 ?s to dissociate, is independent of proton transport residues aR210 and cD61, and behaves as a leash that allows rotary motion of the c-ring to a limit of ?36° while engaged. This leash behaviour satisfies a requirement of a Brownian ratchet mechanism for the F? motor where c-ring rotational diffusion is limited to 36°.

| S-EPMC3020647 | biostudies-literature

Structure of the c14 rotor ring of the proton translocating chloroplast ATP synthase.

Project description:The structure of the membrane integral rotor ring of the proton translocating F(1)F(0) ATP synthase from spinach chloroplasts was determined to 3.8 A resolution by x-ray crystallography. The rotor ring consists of 14 identical protomers that are symmetrically arranged around a central pore. Comparisons with the c(11) rotor ring of the sodium translocating ATPase from Ilyobacter tartaricus show that the conserved carboxylates involved in proton or sodium transport, respectively, are 10.6-10.8 A apart in both c ring rotors. This finding suggests that both ATPases have the same gear distance despite their different stoichiometries. The putative proton-binding site at the conserved carboxylate Glu(61) in the chloroplast ATP synthase differs from the sodium-binding site in Ilyobacter. Residues adjacent to the conserved carboxylate show increased hydrophobicity and reduced hydrogen bonding. The crystal structure reflects the protonated form of the chloroplast c ring rotor. We propose that upon deprotonation, the conformation of Glu(61) is changed to another rotamer and becomes fully exposed to the periphery of the ring. Reprotonation of Glu(61) by a conserved arginine in the adjacent a subunit returns the carboxylate to its initial conformation.

| S-EPMC2709358 | biostudies-literature

Protonation-dependent stepped rotation of the F-type ATP synthase c-ring observed by single-molecule measurements.

Project description:The two opposed rotary molecular motors of the F0F1-ATP synthase work together to provide the majority of ATP in biological organisms. Rotation occurs in 120° power strokes separated by dwells when F1 synthesizes or hydrolyzes ATP. F0 and F1 complexes connect via a central rotor stalk and a peripheral stator stalk. A major unresolved question is the mechanism in which the interaction between subunit-a and rotating subunit-c-ring in the F0 motor uses the flux of H+ across the membrane to induce clockwise rotation against the force of counterclockwise rotation driven by the F1-ATPase. In single-molecule measurements of F0F1 embedded in lipid bilayer nanodiscs, we observed that the ability of the F0 motor to form transient dwells increases with decreasing pH. Transient dwells can halt counterclockwise rotation powered by the F1-ATPase in steps equivalent to the rotation of single c-subunits in the c-ring of F0, and can push the common axle shared by the two motors clockwise by as much as one c-subunit. Because the F0 proton half-channels that access the periplasm and the cytoplasm are exposed to the same pH, these data are consistent with the conclusion that the periplasmic half-channel is more easily protonated in a manner that halts ATPase-driven rotation by blocking ATPase-dependent proton pumping. The fit of transient dwell occurrence to the sum of three Gaussian curves suggests that the asymmetry of the three ATPase-dependent 120° power strokes imposed by the relative positions of the central and peripheral stalks affects c-subunit stepping efficiency.

| S-EPMC5641864 | biostudies-literature

Nitration of specific tyrosines in FoF1 ATP synthase and activity loss in aging.

Project description:It has been reported that C-nitration of proteins occurs under nitrative/oxidative stress; however, its role in pathophysiological situations is not fully understood. In this study, we determined that nitration of Tyr(345) and Tyr(368) in the beta-subunit of the mitochondrial F(o)F(1)-ATPase is a major target for nitrative stress in rat liver under in vivo conditions. The chemical characteristics of these Tyr make them suitable for a facilitated nitration (solvent accessibility, consensus sequence, and pK(a)). Moreover, beta-subunit nitration increased significantly with the age of the rats (from 4 to 80 weeks old) and correlated with decreased ATP hydrolysis and synthesis rates. Although its affinity for ATP binding was unchanged, maximal ATPase activity decreased between young and old rats by a factor of two. These changes directly impacted the available ATP concentration in vivo, and it was expected that they would affect multiple cellular ATP-dependent processes. For instance, at least 50% of available [ATP] in the liver of older rats would have to be committed to sustain maximal Na(+)-K(+)-ATPase activity, whereas only 30% would be required for young rats. If this requirement was not fulfilled, the osmoregulation and Na(+)-nutrient cotransport in liver of older rats would be compromised. On the basis of our studies, we propose that targeted nitration of the beta-subunit is an early marker for nitrative stress and aging.

| S-EPMC2867368 | biostudies-literature

A new type of proton coordination in an F(1)F(o)-ATP synthase rotor ring.

Project description:We solved the crystal structure of a novel type of c-ring isolated from Bacillus pseudofirmus OF4 at 2.5 A, revealing a cylinder with a tridecameric stoichiometry, a central pore, and an overall shape that is distinct from those reported thus far. Within the groove of two neighboring c-subunits, the conserved glutamate of the outer helix shares the proton with a bound water molecule which itself is coordinated by three other amino acids of outer helices. Although none of the inner helices contributes to ion binding and the glutamate has no other hydrogen bonding partner than the water oxygen, the site remains in a stable, ion-locked conformation that represents the functional state present at the c-ring/membrane interface during rotation. This structure reveals a new, third type of ion coordination in ATP synthases. It appears in the ion binding site of an alkaliphile in which it represents a finely tuned adaptation of the proton affinity during the reaction cycle.

| S-EPMC2914638 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data