The Structure of cbb3 Cytochrome Oxidase Provides Insights into Proton Pumping

Science ◽  
2010 ◽  
Vol 329 (5989) ◽  
pp. 327-330 ◽  
Author(s):  
S. Buschmann ◽  
E. Warkentin ◽  
H. Xie ◽  
J. D. Langer ◽  
U. Ermler ◽  
...  
Keyword(s):  
Cytochrome Oxidase ◽  
Proton Pumping

Theoretical Study of the Energetics of Proton Pumping and Oxygen Reduction in Cytochrome Oxidase

2003 ◽  
Vol 107 (39) ◽  
pp. 10946-10955 ◽  
Author(s):  
Per E. M. Siegbahn ◽  
Margareta R. A. Blomberg ◽  
Mattias L. Blomberg
Keyword(s):  
Oxygen Reduction ◽  
Cytochrome Oxidase ◽  
Theoretical Study ◽  
Proton Pumping

A Ligand-Exchange Mechanism of Proton Pumping Involving Tyrosine-422 of Subunit I of Cytochrome Oxidase Is Ruled Out†

Biochemistry ◽  
1996 ◽  
Vol 35 (3) ◽  
pp. 824-828 ◽  
Author(s):  
David M. Mitchell ◽  
Pia Ädelroth ◽  
Jonathan P. Hosler ◽  
John R. Fetter ◽  
Peter Brzezinski ◽  
...  
Keyword(s):  
Cytochrome Oxidase ◽  
Ligand Exchange ◽  
Proton Pumping ◽  
Exchange Mechanism

Effect of diethyl pyrocarbonate modification on spectral and steady-state kinetic properties of bovine heart cytochrome oxidase

1992 ◽  
Vol 70 (7) ◽  
pp. 565-572
Author(s):  
John D. Doran ◽  
Bruce C. Hill
Keyword(s):  
Electron Transfer ◽  
Steady State ◽  
Cytochrome Oxidase ◽  
Proton Pumping ◽  
Kinetic Properties ◽  
High Turnover ◽  
Bovine Heart ◽  
Diethyl Pyrocarbonate ◽  
Steady State Kinetic ◽  
State Kinetic

The histidine-specific reagent diethyl pyrocarbonate has been used to chemically modify bovine heart cytochrome oxidase. Thirty-two of sixty-seven histidine residues of cytochrome oxidase are accessible to modification by diethyl pyrocarbonate. Effects on the Soret and α bands of the heme spectrum indicate disturbance in the environment of one or both of the heme groups. However, diethyl pyrocarbonate modification does not alter the 830-nm absorbance band, suggesting that the environment of CuA is unchanged. Maximal modification of cytochrome oxidase by diethyl pyrocarbonate results in loss of 85–90% of the steay-state electron transfer activity, which can be reversed by hydroxylamine treatment. However, modification of the first 20 histidines does not alter either activity or the heme spectrum, but only when 32 residues have been modified are the activity and heme spectral changes complete. The steady-state kinetic profile of fully modified oxidase is monophasic; the phase corresponding to tight cytochrome c binding and low turnover is retained, whereas the high turnover phase is abolished. Proteoliposomes incorporated with modified oxidase have a 65% lower respiratory control ratio and 40% lower proton pumping stoichiometry than liposomes containing unmodified oxidase. These results are discussed in terms of a redox-linked proton pumping model for energy coupling via cytochrome oxidase.Key words: cytochrome oxidase, histidine modification, electron transfer, proton pumping, diethyl pyrocarbonate.

scholarly journals Cytochrome cbb3 of Thioalkalivibrio is a Na+-pumping cytochrome oxidase

2015 ◽  
Vol 112 (25) ◽  
pp. 7695-7700 ◽  
Author(s):  
Maria S. Muntyan ◽  
Dmitry A. Cherepanov ◽  
Anssi M. Malinen ◽  
Dmitry A. Bloch ◽  
Dimitry Y. Sorokin ◽  
...  
Keyword(s):  
Cytochrome Oxidase ◽  
Respiratory Chain ◽  
Pathogenic Bacteria ◽  
Proton Pumping ◽  
X Ray ◽  
Structure Information ◽  
Unknown Structure ◽  
Alkaliphilic Bacterium ◽  
Ion Pumping ◽  
Insight Into

Cytochrome c oxidases (Coxs) are the basic energy transducers in the respiratory chain of the majority of aerobic organisms. Coxs studied to date are redox-driven proton-pumping enzymes belonging to one of three subfamilies: A-, B-, and C-type oxidases. The C-type oxidases (cbb3 cytochromes), which are widespread among pathogenic bacteria, are the least understood. In particular, the proton-pumping machinery of these Coxs has not yet been elucidated despite the availability of X-ray structure information. Here, we report the discovery of the first (to our knowledge) sodium-pumping Cox (Scox), a cbb3 cytochrome from the extremely alkaliphilic bacterium Thioalkalivibrio versutus. This finding offers clues to the previously unknown structure of the ion-pumping channel in the C-type Coxs and provides insight into the functional properties of this enzyme.

A Mutation in Subunit I of Cytochrome Oxidase fromRhodobacter sphaeroidesResults in an Increase in Steady-State Activity but Completely Eliminates Proton Pumping†

Biochemistry ◽  
2002 ◽  
Vol 41 (45) ◽  
pp. 13417-13423 ◽  
Author(s):  
Ashtamurthy S. Pawate ◽  
Joel Morgan ◽  
Andreas Namslauer ◽  
Denise Mills ◽  
Peter Brzezinski ◽  
...  
Keyword(s):  
Steady State ◽  
Cytochrome Oxidase ◽  
Proton Pumping ◽  
State Activity ◽  
Steady State Activity
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