stoichiometry of the number of protons required to be transferred for each
ATP synthesized remains an open question. A full rotation of the enzyme
should lead to the synthesis of three molecules of ATP. If we assume that
each c subunit translocates one proton per cycle, then the H
+
/ATP ratio is
given by the number of c subunits divided by three. However, the number
of protons is related to the rotation of the c ring but the number of c subunits in the F 0 domain is not the same for enzymes isolated from different organisms. For an enzyme with 12 c subunits, the ratio is 12H
+
/3ATP
or 4H
+
/ATP. With a range of 10–14 for the number of c subunits, the calculated ratio is 4.67:3.33 H
+
/ATP. Whereas an integer value for H
+
/ATP
would make life simple as the gearing is direct, the ratio may be a noninteger due to nonlinear responses which have not yet been identified.
CHAPTER 6
REDOX REACTIONS AND BIOENERGETICS
131
REFERENCES
Abrahams, J.P., Leslie, A.G.W., Lutter, R., and
Walker, J.E. (1994) Structure at 2.8 Å resolution
of F 1 -ATPase from bovine heart mitochondria.
Nature 370, 621–8.
Berry, E.A. and Huang, L. (2003) Observations concerning the quinol oxidation site of the cytochrome
bc 1 complex. FEBS Letters 555, 13–20.
Boyer, P.D. (2000) Catalytic site forms and controls
in ATP synthase catalysis. Biochimica Biophysica Acta
1438, 252–62.
Crofts, A.R. and Berry, E.A. (1998) Structure and
function of the cytochrome bc 1 complex of mitochondria and photosynthetic bacteria. Current
Opinions in Structural Biology 8, 501–9.
Darrouzet, E., Moser, C.C., Dutton, P.L., and Daldal,
F. (2001) Large scale domain movement in cytochrome bc 1 : a new device for electron transfer
in proteins. Trends in Biochemical Sciences 26,
445–51.
Iverson, T.M., Luna-Chavez, C., Cecchini, G., and
Rees, D.C. (1999) Structure of the Escherichia coli
fumerate reductase respiratory complex. Science
284, 1961–6.
Iwata, S., Lee, J.W., Okada, K. et al. (1998) Complete
structure of the 11-subunit bovine mitrochondrial
cytochrome bc 1 complex. Science 281, 64–71.
Jagendorf, A.T. (1998) Chance, luck, and photosynthesis research: an inside story. Photosynthesis
Research 57, 217–29.
Junge, W. and Nelson, N. (2005) Nature’s rotary electromotors. Science 308, 642–4.
Kinosita, K., Adachi, K., and Itoh, H. (2004) Rotation of F1-ATPase: how an atp-driven molecular
machine may work. Annual Re9iew of Biophysics
and Biomolecular Structure 33, 245–68.
Lancaster, C.R.D., Kröger, A., Auer, M., and Michel,
H. (1999) Structure of fumerate reductase from
Wolinella succinogenes at 2.2 Å resolution. Nature 402,
377–85.
Lange, C. and Hunte, C. (2002) Crystal structure of
the yeast cytochrome bc 1 complex with its bound
substrate cytochrome c. Proceedings of the National
Academy of Sciences USA 99, 2800–5.
Meier, T., Polzer, P., Diederichs, K., Welte, W., and
Dimroth, P. (2005) Structure of the rotot ring of
F-type Na
+
-ATPase from Iyobacter tartaricus. Science
308, 659–62.
Murata, T., Yamato, I., Kakinuma, Y., Leslie, A.G.W.,
and Walker, J.E. (2005) Structure of the rotor of the
V-type Na
+
-ATPase from Enterococcus hirae. Science
308, 654–9.
Sarasta, M. (1999) Oxidative phosphorylation at the
fin de siecle. Science 283, 1488–93.
Sazanov, L.A. and Hinchiffe, P. (2006) Structure of
the hydrophilic domain of respiratory complex I
from Thermus thermophilus. Science 311, 1430–6.
Xia, D., Yu, C.A., Kim, H. et al. (1997) Crystal structure of the cytochrome bc 1 complex from bovine
heart mitochondria. Science 277, 60–6.
Yankovskaya, V., Horsefield, R., Tornroth, S. et al.
(2003) Architecture of succinate dehydrogenase and
reactive oxygen species generation. Science 299,
700–4.
Zhang, Z., Huang, L., Schumleister, V.M. et al.
(1998) Electron transfer by domain movement in
cytochrome bc 1 . Nature 392, 677–84.
9781405124362_4_006.qxd 4/29/08 14:07 Page 131
ATP synthesized remains an open question. A full rotation of the enzyme
should lead to the synthesis of three molecules of ATP. If we assume that
each c subunit translocates one proton per cycle, then the H
+
/ATP ratio is
given by the number of c subunits divided by three. However, the number
of protons is related to the rotation of the c ring but the number of c subunits in the F 0 domain is not the same for enzymes isolated from different organisms. For an enzyme with 12 c subunits, the ratio is 12H
+
/3ATP
or 4H
+
/ATP. With a range of 10–14 for the number of c subunits, the calculated ratio is 4.67:3.33 H
+
/ATP. Whereas an integer value for H
+
/ATP
would make life simple as the gearing is direct, the ratio may be a noninteger due to nonlinear responses which have not yet been identified.
CHAPTER 6
REDOX REACTIONS AND BIOENERGETICS
131
REFERENCES
Abrahams, J.P., Leslie, A.G.W., Lutter, R., and
Walker, J.E. (1994) Structure at 2.8 Å resolution
of F 1 -ATPase from bovine heart mitochondria.
Nature 370, 621–8.
Berry, E.A. and Huang, L. (2003) Observations concerning the quinol oxidation site of the cytochrome
bc 1 complex. FEBS Letters 555, 13–20.
Boyer, P.D. (2000) Catalytic site forms and controls
in ATP synthase catalysis. Biochimica Biophysica Acta
1438, 252–62.
Crofts, A.R. and Berry, E.A. (1998) Structure and
function of the cytochrome bc 1 complex of mitochondria and photosynthetic bacteria. Current
Opinions in Structural Biology 8, 501–9.
Darrouzet, E., Moser, C.C., Dutton, P.L., and Daldal,
F. (2001) Large scale domain movement in cytochrome bc 1 : a new device for electron transfer
in proteins. Trends in Biochemical Sciences 26,
445–51.
Iverson, T.M., Luna-Chavez, C., Cecchini, G., and
Rees, D.C. (1999) Structure of the Escherichia coli
fumerate reductase respiratory complex. Science
284, 1961–6.
Iwata, S., Lee, J.W., Okada, K. et al. (1998) Complete
structure of the 11-subunit bovine mitrochondrial
cytochrome bc 1 complex. Science 281, 64–71.
Jagendorf, A.T. (1998) Chance, luck, and photosynthesis research: an inside story. Photosynthesis
Research 57, 217–29.
Junge, W. and Nelson, N. (2005) Nature’s rotary electromotors. Science 308, 642–4.
Kinosita, K., Adachi, K., and Itoh, H. (2004) Rotation of F1-ATPase: how an atp-driven molecular
machine may work. Annual Re9iew of Biophysics
and Biomolecular Structure 33, 245–68.
Lancaster, C.R.D., Kröger, A., Auer, M., and Michel,
H. (1999) Structure of fumerate reductase from
Wolinella succinogenes at 2.2 Å resolution. Nature 402,
377–85.
Lange, C. and Hunte, C. (2002) Crystal structure of
the yeast cytochrome bc 1 complex with its bound
substrate cytochrome c. Proceedings of the National
Academy of Sciences USA 99, 2800–5.
Meier, T., Polzer, P., Diederichs, K., Welte, W., and
Dimroth, P. (2005) Structure of the rotot ring of
F-type Na
+
-ATPase from Iyobacter tartaricus. Science
308, 659–62.
Murata, T., Yamato, I., Kakinuma, Y., Leslie, A.G.W.,
and Walker, J.E. (2005) Structure of the rotor of the
V-type Na
+
-ATPase from Enterococcus hirae. Science
308, 654–9.
Sarasta, M. (1999) Oxidative phosphorylation at the
fin de siecle. Science 283, 1488–93.
Sazanov, L.A. and Hinchiffe, P. (2006) Structure of
the hydrophilic domain of respiratory complex I
from Thermus thermophilus. Science 311, 1430–6.
Xia, D., Yu, C.A., Kim, H. et al. (1997) Crystal structure of the cytochrome bc 1 complex from bovine
heart mitochondria. Science 277, 60–6.
Yankovskaya, V., Horsefield, R., Tornroth, S. et al.
(2003) Architecture of succinate dehydrogenase and
reactive oxygen species generation. Science 299,
700–4.
Zhang, Z., Huang, L., Schumleister, V.M. et al.
(1998) Electron transfer by domain movement in
cytochrome bc 1 . Nature 392, 677–84.
9781405124362_4_006.qxd 4/29/08 14:07 Page 131