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Presentation by: Juan Barrera & Jacqueline Bui
http://www.life.illinois.edu/crofts/bioph354/images/bc1-
stereodimer3.gif
 This is the third
complex in electron
transport chain.
 It is a transmembrane
protein.
 Role is to generate
ATP.
 Located in
Mitochondria.
 Contains 3 respiratory
subunits.
http://www.macromol.uni-osnabrueck.de/bilderhp/mulk1.gif
 Contains a total of 11
subunits.
 There are four redox
centres, namely,two
haem groups, bH and
bL, of cytochrome b,
one haem group in
cytochrome c1, and one
iron–sulphur cluster of
the Rieske protein.
 3 of the subunits are
respiratory.
 2 subunits are core
proteins.
http://www.nature.com/nature/journal/v392/n6677/fig_tab/392677a0_T1.
html
 Quinol is oxidized at
the Q-site of the
complex.
 Quinol Oxidation
occurs in a bifurcated
reaction.
 The high potential chain
is cyt 1 and cyt c.
 The low potential chaon
consists of two cyt b
hemes.
http://www.life.illinois.edu/crofts/bioph354/bc-complex_summary.html
 CoQH2 carries 2
protons across the
inner membrane.
 Two protons pumped
out of the matrix.
http://4.bp.blogspot.com/-
q6aEZzX6Xg0/U4wtlYxqMRI/AAAAAAAABKA/L--
Z0JMMgp8/s1600/Complexo+3.png
 It is inhibited by
antimycin A.
 This leads to leakage
of electrons that
reduce molecular
oxygen.
 There are several
consequences as a
result of inhibition.
http://3.bp.blogspot.com/-
zMwjBlZMnr4/T1FiW2NqNsI/AAAAAAAAAOc/lRRf5Yebumw/s1600/inh
ibotors+of+Electron+transprot+chain.jpg
 Iwata, So, et al. "Complete Structure Of The 11-Subunit Bovine Mitochondrial Cytochrome Bc1 Complex."
Science 281.5373 (1998): 64-71. Academic Search Complete. Web. 7 Nov. 2014.
 Xiao, Y, Esser, L, Zhou, F, Li, C, Zhou, Y, Yu, C, Qin, Z, & Xia, D 2014, 'Studies on Inhibition of Respiratory
Cytochrome bc1 Complex by the Fungicide Pyrimorph Suggest a Novel Inhibitory Mechanism', Plos ONE, 9, 4,
pp. 1-12, Academic Search Complete, EBSCOhost, viewed 7 November 2014.
 Zhang, Z, Huang, L, Shulmeister, V, Chi, Y, Kim, K, Hung, L, Crofts, A, Berry, E, & Kim, S 1998, 'Electron
transfer by domain movement in cytochrome bc1', Nature, 392, 6677, p. 677, Academic Search Complete,
EBSCOhost, viewed 7 November 2014.
 http://3.bp.blogspot.com/-
zMwjBlZMnr4/T1FiW2NqNsI/AAAAAAAAAOc/lRRf5Yebumw/s1600/inhibotors+of+Electron+transprot+c
hain.jpg
 http://4.bp.blogspot.com/-q6aEZzX6Xg0/U4wtlYxqMRI/AAAAAAAABKA/L--
Z0JMMgp8/s1600/Complexo+3.png
 www.life.illinois.edu/crofts/bioph354/bc-complex_summary.html
 http://www.macromol.uni-osnabrueck.de/bilderhp/mulk1.gif
 http://www.life.illinois.edu/crofts/bioph354/images/bc1-stereodimer3.gif

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Ubiquinol-Cytochrome C Oxidoreductase (Respiratory Complex III)

  • 1. Presentation by: Juan Barrera & Jacqueline Bui http://www.life.illinois.edu/crofts/bioph354/images/bc1- stereodimer3.gif
  • 2.  This is the third complex in electron transport chain.  It is a transmembrane protein.  Role is to generate ATP.  Located in Mitochondria.  Contains 3 respiratory subunits. http://www.macromol.uni-osnabrueck.de/bilderhp/mulk1.gif
  • 3.  Contains a total of 11 subunits.  There are four redox centres, namely,two haem groups, bH and bL, of cytochrome b, one haem group in cytochrome c1, and one iron–sulphur cluster of the Rieske protein.  3 of the subunits are respiratory.  2 subunits are core proteins. http://www.nature.com/nature/journal/v392/n6677/fig_tab/392677a0_T1. html
  • 4.  Quinol is oxidized at the Q-site of the complex.  Quinol Oxidation occurs in a bifurcated reaction.  The high potential chain is cyt 1 and cyt c.  The low potential chaon consists of two cyt b hemes. http://www.life.illinois.edu/crofts/bioph354/bc-complex_summary.html
  • 5.  CoQH2 carries 2 protons across the inner membrane.  Two protons pumped out of the matrix. http://4.bp.blogspot.com/- q6aEZzX6Xg0/U4wtlYxqMRI/AAAAAAAABKA/L-- Z0JMMgp8/s1600/Complexo+3.png
  • 6.  It is inhibited by antimycin A.  This leads to leakage of electrons that reduce molecular oxygen.  There are several consequences as a result of inhibition. http://3.bp.blogspot.com/- zMwjBlZMnr4/T1FiW2NqNsI/AAAAAAAAAOc/lRRf5Yebumw/s1600/inh ibotors+of+Electron+transprot+chain.jpg
  • 7.  Iwata, So, et al. "Complete Structure Of The 11-Subunit Bovine Mitochondrial Cytochrome Bc1 Complex." Science 281.5373 (1998): 64-71. Academic Search Complete. Web. 7 Nov. 2014.  Xiao, Y, Esser, L, Zhou, F, Li, C, Zhou, Y, Yu, C, Qin, Z, & Xia, D 2014, 'Studies on Inhibition of Respiratory Cytochrome bc1 Complex by the Fungicide Pyrimorph Suggest a Novel Inhibitory Mechanism', Plos ONE, 9, 4, pp. 1-12, Academic Search Complete, EBSCOhost, viewed 7 November 2014.  Zhang, Z, Huang, L, Shulmeister, V, Chi, Y, Kim, K, Hung, L, Crofts, A, Berry, E, & Kim, S 1998, 'Electron transfer by domain movement in cytochrome bc1', Nature, 392, 6677, p. 677, Academic Search Complete, EBSCOhost, viewed 7 November 2014.  http://3.bp.blogspot.com/- zMwjBlZMnr4/T1FiW2NqNsI/AAAAAAAAAOc/lRRf5Yebumw/s1600/inhibotors+of+Electron+transprot+c hain.jpg  http://4.bp.blogspot.com/-q6aEZzX6Xg0/U4wtlYxqMRI/AAAAAAAABKA/L-- Z0JMMgp8/s1600/Complexo+3.png  www.life.illinois.edu/crofts/bioph354/bc-complex_summary.html  http://www.macromol.uni-osnabrueck.de/bilderhp/mulk1.gif  http://www.life.illinois.edu/crofts/bioph354/images/bc1-stereodimer3.gif