Recombinant Escherichia coli Cytochrome o ubiquinol oxidase subunit 3 (cyoC)
Description
Overview of cyoC
The cytochrome o ubiquinol oxidase subunit 3 (cyoC) is a core component of the E. coli cytochrome bo<sub>3</sub> ubiquinol oxidase complex, a four-subunit heme-copper oxidase central to aerobic respiration. This enzyme catalyzes the oxidation of ubiquinol (UQH<sub>2</sub>) to ubiquinone (UQ) and the four-electron reduction of oxygen to water, while pumping protons across the bacterial membrane . Recombinant cyoC (accession P0ABJ3) is a truncated, engineered version of the native subunit, optimized for expression and purification in heterologous systems. It spans 204 amino acids and contains five transmembrane helices, distinguishing it from eukaryotic homologs with additional spans .
Production and Purification
Recombinant cyoC is produced via heterologous expression, typically in E. coli, with an N-terminal His-tag for affinity chromatography . Key steps include:
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Expression: Inducible promoters (e.g., T7-lac) drive cyoC synthesis in E. coli strains like BL21(DE3) .
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Membrane Preparation: Harvesting of inclusion bodies or membrane fractions, followed by solubilization in detergents (e.g., DDM) .
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Purification: Ni<sup>2+</sup>-affinity chromatography and size-exclusion chromatography (SEC) for monodispersity .
| Method | Application | Yield |
|---|---|---|
| In Vitro Expression | Cell-free systems for rapid production | High purity |
| Baculovirus/Sf9 Cells | For eukaryotic post-translational modifications (rarely used for cyoC) | Moderate yield |
| Bacterial Expression | Cost-effective, scalable; standard for cyoC production | High yield |
Functional Role in the bo<sub>3</sub> Complex
cyoC interacts with subunits I (cyoB) and IV (cyoD) to form the core of the oxidase. Its structural role includes:
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Stabilizing Heme Centers: Anchoring heme b and o<sub>3</sub> in subunit I for electron transfer .
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Proton Translocation: Contributing to the proton-conducting pathway through membrane-spanning helices .
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Substrate Binding: Facilitating ubiquinol access to the active site via hydrophilic channels .
Inactivation of cyoC disrupts the oxidase complex, impairing aerobic respiration and relieving catabolic repression in E. coli .
Biotechnological Relevance
Product Specs
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Note: All proteins are shipped with standard blue ice packs. If you require dry ice shipping, please inform us in advance as additional charges will apply.
Generally, the shelf life of liquid form is 6 months at -20°C/-80°C. Lyophilized form has a shelf life of 12 months at -20°C/-80°C.
Target Background
KEGG: ecj:JW0420
STRING: 316385.ECDH10B_0386
