Recombinant Saccharomyces cerevisiae Cytochrome oxidase assembly protein 3, mitochondrial (COA3)
Description
Overview of COA3
Recombinant COA3 is a bioengineered protein derived from Saccharomyces cerevisiae (baker’s yeast), expressed in Escherichia coli and purified to >90% homogeneity . It is critical for the assembly of mitochondrial cytochrome oxidase (Complex IV), the terminal enzyme in the electron transport chain. COA3 functions alongside Cox14 to regulate the translation of COX1 mRNA, encoding the mitochondrially synthesized core subunit of Complex IV .
| Characteristic | Details |
|---|---|
| Source | S. cerevisiae (strain RM11-1a) |
| Tag | N-terminal His-tag |
| Expression System | E. coli |
| Purity | >90% (SDS-PAGE) |
| Sequence Coverage | Full-length (1–85 amino acids) |
| Molecular Weight | ~9.88 kDa |
| Storage Buffer | Tris-based buffer, 50% glycerol |
Mechanism of Action in Cytochrome Oxidase Assembly
COA3 participates in a negative feedback loop to couple COX1 translation with Complex IV biogenesis:
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Assembly Intermediates: Newly synthesized Cox1 associates with COA3 and Cox14, forming early complexes (250–400 kDa) .
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Mss51 Sequestration: COA3 recruits Mss51 to these complexes, preventing its interaction with COX1 mRNA .
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Latent State Formation: The COA3–Cox14–Cox1–Mss51 complex inactivates Mss51, halting COX1 translation until assembly progresses .
| Component | Role in Regulation |
|---|---|
| COA3 | Anchors Mss51 to Cox1-containing complexes; promotes latent Mss51 state |
| Cox14 | Stabilizes COA3–Cox1 interactions; required for Mss51 binding |
| Mss51 | Translational activator of COX1; inactivated in COA3–Cox14 complexes |
| Coa1 | Binds to Mss51 in COA3–Cox14 complexes, enhancing inactivation |
Deficiency Phenotypes
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Growth Defects: coa3Δ mutants show respiratory growth impairment on nonfermentable substrates (e.g., glycerol) .
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Cox1 Accumulation: Absence of COA3 traps Mss51 in its active state, leading to unregulated COX1 synthesis and Cox1 degradation due to misassembly .
Recombinant Protein Applications
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Structural Studies: Used to map interactions with Cox14, Shy1, and Mss51 via co-immunoprecipitation and BN-PAGE .
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Therapeutic Relevance: Potential target for modulating mitochondrial respiration in diseases linked to Complex IV dysfunction (e.g., neurodegenerative disorders) .
Sequence and Biochemical Features
The recombinant COA3 protein (1–85 aa) includes:
| Amino Acid Residues | Function |
|---|---|
| 1–20 | Signal for mitochondrial targeting (predicted) |
| 21–40 | Transmembrane helix (integral membrane embedding) |
| 41–85 | C-terminal domain for Cox1/Mss51 interactions |
Experimental Validation and Challenges
Product Specs
Note: We prioritize shipping the format currently in stock. However, if you have specific requirements for the format, please indicate them in your order. We will prepare the product according to your request.
Note: All our proteins are shipped with standard blue ice packs. If you require dry ice shipping, please inform us in advance. Additional fees will apply.
Generally, the shelf life of liquid form is 6 months at -20°C/-80°C. The shelf life of lyophilized form is 12 months at -20°C/-80°C.
