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Interactions of subunits Asa2, Asa4 and Asa7 in the peripheral stalk of the mitochondrial ATP synthase of the chlorophycean alga Polytomella sp
- Source :
- Biochimica et biophysica acta. 1837(1)
- Publication Year :
- 2013
-
Abstract
- Mitochondrial F1FO-ATP synthase of chlorophycean algae is a complex partially embedded in the inner mitochondrial membrane that is isolated as a highly stable dimer of 1600kDa. It comprises 17 polypeptides, nine of which (subunits Asa1 to 9) are not present in classical mitochondrial ATP synthases and appear to be exclusive of the chlorophycean lineage. In particular, subunits Asa2, Asa4 and Asa7 seem to constitute a section of the peripheral stalk of the enzyme. Here, we over-expressed and purified subunits Asa2, Asa4 and Asa7 and the corresponding amino-terminal and carboxy-terminal halves of Asa4 and Asa7 in order to explore their interactions in vitro, using immunochemical techniques, blue native electrophoresis and affinity chromatography. Asa4 and Asa7 interact strongly, mainly through their carboxy-terminal halves. Asa2 interacts with both Asa7 and Asa4, and also with subunit α in the F1 sector. The three Asa proteins form an Asa2/Asa4/Asa7 subcomplex. The entire Asa7 and the carboxy-terminal half of Asa4 seem to be instrumental in the interaction with Asa2. Based on these results and on computer-generated structural models of the three subunits, we propose a model for the Asa2/Asa4/Asa7 subcomplex and for its disposition in the peripheral stalk of the algal ATP synthase.
- Subjects :
- Models, Molecular
Protein subunit
Dimeric mitochondrial complex V
Biophysics
Chlorophycean algae
Chlamydomonas reinhardtii
Biochemistry
Affinity chromatography
F1FO-ATP synthase peripheral-stalk
Computer Simulation
Polytomella sp
Amino Acid Sequence
Inner mitochondrial membrane
chemistry.chemical_classification
Asa subunits
ATP synthase
biology
Polytomella
Cell Biology
Mitochondrial Proton-Translocating ATPases
biology.organism_classification
Mitochondria
Protein Subunits
Enzyme
Stalk
chemistry
Multiprotein Complexes
Mitochondrial Membranes
biology.protein
Electrophoresis, Polyacrylamide Gel
Peptides
Volvocida
Dimerization
Subjects
Details
- ISSN :
- 00063002
- Volume :
- 1837
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Biochimica et biophysica acta
- Accession number :
- edsair.doi.dedup.....1a383773c533d8d5569691d53b130055