Recombinant Kluyveromyces lactis Cytochrome oxidase assembly protein 3, mitochondrial (COA3)
Description
Key Interactions
Negative Feedback Regulation
COA3 and Cox14 form assembly intermediates with newly synthesized Cox1, enabling Mss51 recruitment. This interaction shifts Mss51 to a latent state, downregulating COX1 translation . In coa3Δ or cox14Δ mutants:
-
Cox1 Accumulation: Unassembled Cox1 is rapidly degraded due to destabilization .
-
Loss of Mss51 Regulation: COX1 expression becomes uncontrolled, leading to respiratory defects .
Membrane Topology
Protease protection assays confirm COA3’s integral membrane localization:
-
C-Terminus: Exposed to the IMS, as shown by degradation upon osmotic swelling .
-
N-Terminus: Likely matrix-facing, based on predicted transmembrane topology .
Mitochondrial Disease Association
While COA3 in K. lactis itself is not directly linked to human diseases, homologs in other organisms (e.g., humans) are implicated in Complex IV deficiencies. Mutations in COA3 homologs can cause:
Research Applications
Recombinant COA3 is used to study:
-
Complex IV Biogenesis: Assembly intermediates and regulatory mechanisms .
-
Protein-Protein Interactions: Binding assays with Cox1, Cox14, and Mss51 .
Expression and Purification
Product Specs
Note: While we prioritize shipping the format currently in stock, please specify your format preference during order placement for fulfillment based on your needs.
Note: All proteins are shipped with standard blue ice packs. Dry ice shipping requires prior arrangement and incurs additional charges.
If you require a specific tag, please inform us, and we will prioritize its development.
Target Background
KEGG: kla:KLLA0F01771g
STRING: 284590.XP_455160.1
Q&A
Basic Research Questions
-
What is Kluyveromyces lactis and why is it used in recombinant protein expression?
Kluyveromyces lactis is a non-Saccharomyces yeast with significant scientific and biotechnological importance. It has gained prominence in recombinant protein production due to its history of safe use in the food industry, as evidenced by its Generally Regarded As Safe (GRAS) status . Unlike Saccharomyces cerevisiae, K. lactis does not tend to hyperglycosylate recombinant proteins and doesn't terminate N-linked carbohydrate chains with potentially allergenic alpha-1,3-linked mannose residues . This yeast can grow to high cell densities and efficiently express heterologous proteins, making it an excellent expression system for research applications . Its ability to assimilate lactose and convert it into lactic acid also provides metabolic advantages in certain expression systems .
-
What is the function of Cytochrome Oxidase Assembly Protein 3 (COA3) in mitochondria?
COA3 is an integral membrane protein that plays a crucial role in the regulation of cytochrome oxidase assembly in mitochondria. Based on research findings, COA3 forms assembly intermediates with newly synthesized Cox1 (a mitochondria-encoded subunit of cytochrome oxidase) and is required for the association of the Mss51 translational activator with these complexes . Together with Cox14, COA3 promotes the formation of a latent translational resting state for Mss51, thereby down-regulating COX1 expression . This represents a negative feedback regulation mechanism where the expression of Cox1 is intimately coupled to its assembly process. In the absence of COA3 function, uncontrolled expression of COX1 occurs due to loss of this feedback regulation, resulting in accumulated unassembled Cox1 that is rapidly degraded .
-
What is the structure and topology of recombinant K. lactis COA3 protein?
Recombinant K. lactis COA3 is a small protein of 88 amino acids with a molecular mass of approximately 9.88 kD . Structurally, it contains a single segment with the potential to represent a transmembrane helix, confirming its nature as an integral membrane protein . Carbonate extraction analyses of isolated mitochondria have shown that COA3 is carbonate-resistant, behaving similarly to other integral membrane proteins . Regarding its topology, protease protection experiments indicate that COA3 exposes its C-terminus to the intermembrane space (IMS) of mitochondria . The full amino acid sequence of K. lactis COA3 is: MLEPSPYQDHKTWKMTPAMIRARQPFFKKNLMGLVILLGVTGTIYTYTYKMLNKDSDFADVPIPPIDEKELEQLKKEYELEKIRRAQK .
