Cytochrome O from Escherichia coli Is Structurally Related to Cytochrome aa3a

Saraste, Matti; Raitio, Mirja; Jalli, Tuulikki; Chepuri, Visala; Lemieux, Laura J.; Gennis, Robert B.

doi:10.1111/j.1749-6632.1988.tb35346.x

Cited by 31 publications

(14 citation statements)

References 15 publications

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“…Although all the results of this work are consistent with the conclusion that the oxidase is a cytochrome co, it is worth noting that the distinctions between type of oxidase (cytochrome aa3, bo or co) and substrate specificity are not as well-defined as they once were; for example, there is considerable structural similarity between the cytochrome aaj from Paracoccus denitrijicans, which oxidizes cytochrome c, and the cytochrome bo of E. coli, whose substrate is the low-potential substrate ubiquinol (Saraste et al, 1988;Raitio et al, 1990).…”

Section: Discussionsupporting

confidence: 82%

“…The cytochrome bo of Escherichia coli is the only example of a functional ubiquinol oxidase of this type that has been characterized extensively (Kita et al, 1984;Saraste et al, 1988). E. coli is a facultative anaerobe which, in aerobic conditions, produces neither c-type nor a-type cytochromes, and it might be reasonable to assume that cytochrome bo would be found only in similar bacteria.…”

Section: H T C Chan and C Anthonymentioning

confidence: 99%

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The o-type oxidase of the acidophilic methylotroph Acetobacter methanolicus

Chan

Anthony

1991

Journal of General Microbiology

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Membranes of the acidophilic methylotroph Acetobucter methanolicus contained only b-and c-type cytochrome and a CO-binding b-type cytochrome. An azide-sensitive oxidase that oxidizes cytochrome c and ascorbatel TMPD was solubilized from the membrane with a mixture of CHAPS and Zwittergent3-12 (1.7 fold increase in specific activity with 32% yield). The solubilized oxidase is unusually stable with respect to high ionic strength (200 mM-NaC1) and stable between pH 4.0 and 6.8. Of the two soluble c-type cytochromes from A. methanoficus only the typical class I cytochrome (cytochrome cH) was a good substrate, as was equine cytochrome c. The oxidase was partially purified by anion-exchange chromatography but further purification proved impossible. The yield with respect to equine cytochrome c oxidation was l8%, with a 22-fold purification, but during purification most of the activity with respect to cytochrome cH and TMPD was lost. Neutral phospholipids had little effect on activity of the oxidase but the charged phospholipids phosphatidylglycerol and phosphatidylserine stimulated activity up to about fourfold. It proved impossible to incorporate the oxidase into active lipoprotein vesicles. During the purification process the pH optimum for oxidation of cytochrome cH was unchanged (pH 5.6) whereas that for oxidation of equine cytochrome changed from pH 9.5 to 7.5 and the sensitivity of the oxidase to azide changed from non-competitive to competitive during the purification process. The partially-purified oxidase contained only btype cytochrome, some of which was CO-reactive. It is proposed that the oxidase is a cytochrome co type of oxidase that loses its cytochrome c component during the purification process and is only able to oxidize c-type cytochromes if these can be formed into a 'reconstituted' cytochrome co with the partially-purified oxidase. IntroductionThe present paper describes work on an unusual o-type oxidase from the acidophilic methylotroph Acetobacter methanolicus, which grows at pH 4 on methanol as its sole carbon and energy source (Steudel & Babel, 1982;Steudel et al., 1980). As in other methylotrophic bacteria, methanol is oxidized by way of the quinoprotein methanol dehydrogenase, its specific electron acceptor cytochrome cL, and a typical class I c-type cytochrome which is oxidized by a membrane oxidase (Anthony, 1982(Anthony, , 1986Elliott & Anthony, 1988). Except for the oxidase all these proteins are periplasmic and so operate at pH4, the pH of the growth medium. Preliminary observations suggested that this oxidase may be more stable to extremes of pH and salt concentration compared with cytochrome oxidases in other bacteria.The bacterial o-type oxidases are defined loosely as oxidases having a CO-binding cytochrome b, which for convenience is usually referred to as cytochrome o and which is assumed to be the oxygen-reactive site. Cytochrome o was first described in Staphylococcus aureus (Chance, 1953 ;Castor & Chance, 1959) and the 0-type oxidases have since been shown to be the most widely...

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Section: Discussionsupporting

confidence: 82%

Section: H T C Chan and C Anthonymentioning

confidence: 99%

The o-type oxidase of the acidophilic methylotroph Acetobacter methanolicus

Chan

Anthony

1991

Journal of General Microbiology

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“…Subunits I, II and III are homologous to the mitochondrial encoded subunits of the eukaryotic (mitochondrial) cytochrome c oxidase [6]. Whereas, in the mitochondrial oxidase subunit II contains the docking site of the cytochrome c substrate and the Cu A redox center, neither of these features is present in the homologous subunit II of the quinol oxidases [7, 8]. The absence of the residues required for copper ligation to Cu A is diagnostic of quinol oxidases and allows one to identify quinol oxidases in genome sequences.…”

Section: Introductionmentioning

confidence: 99%

The quinone-binding sites of the cytochrome bo3 ubiquinol oxidase from Escherichia coli

Yap

Lin

Ouyang

et al. 2010

Biochimica et Biophysica Acta (BBA) - Bioenergetics

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Summary Cytochrome bo3 is the major respiratory oxidase located in the cytoplasmic membrane of E. coli when grown under high oxygen tension. The enzyme catalyzes the 2-electron oxidation of ubiquinol-8 and the 4-electron reduction of dioxygen to water. When solubilized and isolated using dodecylmaltoside, the enzyme contains one equivalent of ubiquinone-8, bound at a high affinity site (QH). The quinone bound at the QH site can form a stable semiquinone, and the amino acid residues which hydrogen bond to the semiquinone have been identified. In the current work, it is shown that the tightly bound ubiquinone-8 at the QH site is not displaced by ubiquinol-1 even during enzyme turnover. Furthermore, the presence of high affinity inhibitors, HQNO and aurachin C1-10, do not displace ubiquinone-8 from the QH site. The data clearly support the existence of a second binding site for ubiquinone, the QL site, which can rapidly exchange with the substrate pool. HQNO is shown to bind to a single site on the enzyme and to prevent formation of the stable ubisemiquinone, though without displacing the bound quinone. Inhibition of the steady state kinetics of the enzyme indicates that aurachin C1-10 may compete for binding with quinol at the QL site while, at the same time, preventing formation of the ubisemiquinone at the QH site. It is suggested that the two quinone binding sites may be adjacent to each other or partially overlap.

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“…The best known are the aa3-type cytochrome-c oxidases having two haem-A units (haem a and a3) and two redox-active copper ions (CuA and CuB), and the cytochrome-bo-type quinol oxidases having two b-type haems, but only one redox-active copper. Cytochrome bo from Escherichia coli is structurally strongly related to the aa3-type cytochrome-c oxidases [2,3], but it lacks the CuA centre typical of the latter [4-61. These oxidases probably bind both haems and one copper (Cu,) to the largest subunit, whilst CuA is probably bound to subunit I1 in the aa3-type oxidases [7, 81. One main difference between aa3-type cytochrome oxidases described so far is that in some thermophilic bacteria (many of which are Bacilli) cytochrome-c is fused to the subunit-I1 polypeptide of the enzyme.…”

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confidence: 99%

Bacillus subtilis expresses two kinds of haem‐A‐containing terminal oxidases

Lauraeus

Haltia

Saraste

et al. 1991

European Journal of Biochemistry

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113

117

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The expression of two different aa3‐type cytochrome oxidases is demonstrated in Bacillus subtilis. One of them (denoted caa3‐605), was predicted by DNA‐sequencing of Bacillus cytochrome oxidase genes, but has not been found previously. It contains covalently bound haem C in subunit II and is very similar to the enzyme previously described in the thermophilic bacterium PS3. The other oxidase (denoted aa3‐600) deviates from most known oxidases of aa3 type, and is probably identical with the oxidase described by de Vrij et al. [de Vrij, W., Azzi, A. & Konings, W. N. (1983) Eur. J. Biochem. 131, 97–103]. It shows no immunological cross‐reactivity to the PS3 enzyme and differs from this spectroscopically; it contains no CuA and does not oxidise cytochrome c despite of its haem‐A chromophores. It catalyses oxidation of quinols, which is proposed to be its physiological function.

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Cytochrome O from Escherichia coli Is Structurally Related to Cytochrome aa₃a

Cited by 31 publications

References 15 publications

The o-type oxidase of the acidophilic methylotroph Acetobacter methanolicus

The o-type oxidase of the acidophilic methylotroph Acetobacter methanolicus

The quinone-binding sites of the cytochrome bo3 ubiquinol oxidase from Escherichia coli

Bacillus subtilis expresses two kinds of haem‐A‐containing terminal oxidases

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