The ATP synthase subunit c (atpH) is a proteolipid that oligomerizes into a rotary c-ring structure embedded in thylakoid membranes. Key structural features include:
Two transmembrane α-helices linked by a polar loop
Oligomeric State
Forms a c₁₄–c₁₅ ring in chloroplasts
Conserved Motifs
GxGxGxG motif in N-terminal helix (critical for ring packing)
Recombinant Production and Purification
Recombinant production enables large-scale studies of this subunit’s biophysical and functional roles:
Expression System: Typically produced in Escherichia coli with codon optimization for high yield.
Tags: May include affinity tags (e.g., maltose-binding protein) during production.
Storage: Stabilized in Tris-based buffer with 50% glycerol at –20°C.
Example Protocol (adapted from spinach homolog studies):
Clone synthetic atpH into pET vector.
Express in E. coli BL21(DE3) with IPTG induction.
Purify via affinity chromatography and ion-exchange steps.
Functional Role in Photosynthesis
The c-ring acts as a proton-driven rotor in ATP synthesis:
Proton Translocation: Each c-subunit binds one proton, and the ring’s rotation drives ATP production in the F₁ sector.
Stoichiometry Impact:
Tobacco engineered with a c₁₅-ring (vs. native c₁₄) maintained growth despite reduced ATP synthase abundance by increasing proton motive force (PMF) contribution.
Larger c-rings require fewer protons per ATP but operate at lower PMF thresholds.
Table 1: Experimental Insights from Transplastomic Studies
Study Focus
Outcome
Source
c₁₅-ring Engineering
Increased PMF compensated for reduced ATP synthase levels, enabling normal growth.
Cytochrome oxidase assembly impaired upon subunit c isoform knockdown (mammalian studies).
Applications and Future Directions
Biophysical Studies: Reconstitution of synthetic c-rings to probe proton coupling efficiency.
Crop Engineering: Modifying c-ring stoichiometry to optimize photosynthetic efficiency under stress.
Drug Discovery: Targeting bacterial homologs (e.g., atpE in Acidovorax) for antibiotic development.
Product Specs
Form
Lyophilized powder Please note: We prioritize shipping the format currently in stock. However, if you require a specific format, please indicate your preference in the order notes. We will fulfill your request if available.
Lead Time
Delivery time may vary depending on the purchase method and location. Please consult your local distributor for specific delivery details. 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.
Notes
Repeated freezing and thawing is not recommended. For optimal stability, store working aliquots at 4°C for up to one week.
Reconstitution
Before opening, we recommend briefly centrifuging the vial to collect the contents at the bottom. Reconstitute the protein in deionized sterile water to a concentration of 0.1-1.0 mg/mL. We recommend adding 5-50% glycerol (final concentration) and aliquoting for long-term storage at -20°C/-80°C. Our default glycerol concentration is 50%. Customers can use this as a reference.
Shelf Life
The shelf life depends on various factors, including storage conditions, buffer ingredients, storage temperature, and the inherent stability of the protein.
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.
Storage Condition
Upon receipt, store at -20°C/-80°C. Aliquoting is recommended for multiple uses. Avoid repeated freeze-thaw cycles.
Tag Info
Tag type is determined during the manufacturing process.
The tag type is determined during production. If you have a specific tag type requirement, please inform us, and we will prioritize developing the specified tag.
Synonyms
atpH; ATP synthase subunit c, chloroplastic; ATP synthase F(0 sector subunit c; ATPase subunit III; F-type ATPase subunit c; F-ATPase subunit c; Lipid-binding protein
F(1)F(0) ATP synthase generates ATP from ADP in the presence of a proton or sodium gradient. F-type ATPases consist of two structural domains: F(1), containing the extramembraneous catalytic core, and F(0), containing the membrane proton channel, connected by a central stalk and a peripheral stalk. During catalysis, ATP synthesis in the catalytic domain of F(1) is coupled via a rotary mechanism of the central stalk subunits to proton translocation. As a key component of the F(0) channel, it plays a direct role in translocation across the membrane. A homomeric c-ring, composed of 10-14 subunits, forms the central stalk rotor element together with the F(1) delta and epsilon subunits.