Interactions of subunits Asa2, Asa4 and Asa7 in the peripheral stalk of the mitochondrial ATP synthase of the chlorophycean alga Polytomella sp.
Por:
Miranda-Astudillo H., Cano-Estrada A., Vázquez-Acevedo M., Colina-Tenorio L., Downie-Velasco A., Cardol P., Remacle C., Domínguez-Ramírez L., González-Halphen D.
Publicada:
1 ene 2014
Resumen:
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 1600 kDa. 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 a 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. © 2013 Elsevier B.V.
Filiaciones:
Miranda-Astudillo H.:
Univ Nacl Autonoma Mexico, Inst Fisiol Celular, Mexico City 04510, DF, Mexico
Cano-Estrada A.:
Univ Nacl Autonoma Mexico, Inst Fisiol Celular, Mexico City 04510, DF, Mexico
Vázquez-Acevedo M.:
Univ Nacl Autonoma Mexico, Inst Fisiol Celular, Mexico City 04510, DF, Mexico
Colina-Tenorio L.:
Univ Nacl Autonoma Mexico, Inst Fisiol Celular, Mexico City 04510, DF, Mexico
Downie-Velasco A.:
Univ Nacl Autonoma Mexico, Inst Fisiol Celular, Mexico City 04510, DF, Mexico
Cardol P.:
Genetics of Microorganisms, Institute of Plant Biology, University of Liège, Liège, Belgium
Remacle C.:
Genetics of Microorganisms, Institute of Plant Biology, University of Liège, Liège, Belgium
Domínguez-Ramírez L.:
Univ Nacl Autonoma Mexico, Inst Fisiol Celular, Mexico City 04510, DF, Mexico
González-Halphen D.:
Univ Nacl Autonoma Mexico, Inst Fisiol Celular, Mexico City 04510, DF, Mexico
All Open Access; Bronze
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