Membrane Topography and Near-neighbor Relationships of the Mitochondrial ATP Synthase Subunits e, f, and g

The well characterized subunits of the bovine ATP synthase complex are the α, β, γ, δ, and ϵ subunits of the catalytic sector, F1; the ATPase inhibitor protein; and subunits a, b, c, and d, OSCP (oligomycin sensitivity-conferring protein), F6, and A6L, which are present in the membrane sector, F0, a...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of biological chemistry 1996-08, Vol.271 (34), p.20340-20345
Main Authors: Belogrudov, Grigory I., Tomich, John M., Hatefi, Youssef
Format: Article
Language:English
Subjects:
Amino Acid Sequence
Animals
Cattle
Chymotrypsin - metabolism
Cross-Linking Reagents
Immunologic Techniques
Macromolecular Substances
Mitochondria, Heart - enzymology
Mitochondria, Heart - ultrastructure
Molecular Sequence Data
Molecular Weight
Proton-Translocating ATPases - chemistry
Proton-Translocating ATPases - ultrastructure
Solubility
Trypsin - metabolism
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The well characterized subunits of the bovine ATP synthase complex are the α, β, γ, δ, and ϵ subunits of the catalytic sector, F1; the ATPase inhibitor protein; and subunits a, b, c, and d, OSCP (oligomycin sensitivity-conferring protein), F6, and A6L, which are present in the membrane sector, F0, and the 45-Å-long stalk that connects F1 to F0. It has been shown recently that bovine ATP synthase preparations also contain three small polypeptides, designated e, f, and g, with respective molecular masses of 8.2, 10.2, and 11.3 kDa. To ascertain their involvement as bona fide subunits of the ATP synthase and to investigate their membrane topography and proximity to the above ATP synthase subunits, polyclonal antipeptide antibodies were raised in the rabbit to the COOH-terminal amino acid residues 57-70 of e, 75-86 of f, and 91-102 of g. It was shown that (i) e, f, and g could be immunoprecipitated with anti-OSCP IgG from a fraction of bovine submitochondrial particles enriched in oligomycin-sensitive ATPase; (ii) the NH2 termini of f and g are exposed on the matrix side of the mitochondrial inner membrane and can be curtailed by proteolysis; (iii) the COOH termini of all three polypeptides are exposed on the cytosolic side of the inner membrane; and (iv) f cross-links to A6L and to g, and e cross-links to g and appears to form an e-e dimer. Thus, the bovine ATP synthase complex appears to have 16 unlike subunits, twice as many as its counterpart in Escherichia coli.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.271.34.20340