TY - JOUR
T1 - Chaperones of F1-ATPase
AU - Ludlam, Anthony
AU - Brunzelle, Joseph
AU - Pribyl, Thomas
AU - Xu, Xingjue
AU - Gatti, Domenico L.
AU - Ackerman, Sharon H.
PY - 2009/6/19
Y1 - 2009/6/19
N2 - Mitochondrial F1-ATPase contains a hexamer of alternating α and β subunits. The assembly of this structure requires two specialized chaperones, Atp11p and Atp12p, that bind transiently to α and β. In the absence of Atp11p and Atp12p, the hexamer is not formed, and α and β precipitate as large insoluble aggregates. An early model for the mechanism of chaperonemediated F1 assembly (Wang, Z. G., Sheluho, D., Gatti, D. L., and Ackerman, S. H. (2000) EMBO J. 19, 1486-1493) hypothesized that the chaperones themselves look very much like the α and β subunits, and proposed an exchange of Atp11p for α and of Atp12p for β; the driving force for the exchange was expected to be a higher affinity of α and β for each other than for the respective chaperone partners. One important feature of this model was the prediction that as long as Atp11p is bound to β and Atp12p is bound to α, the two F1 subunits cannot interact at either the catalytic site or the noncatalytic site interface. Here we present the structures of Atp11p from Candida glabrata and Atp12p from Paracoccus denitrificans, and we show that some features of the Wang model are correct, namely that binding of the chaperones to α and β prevents further interactions between these F1 subunits. However, Atp11p and Atp12p do not resemble α or β, and it is instead the F1 γ subunit that initiates the release of the chaperones from α and β and their further assembly into the mature complex.
AB - Mitochondrial F1-ATPase contains a hexamer of alternating α and β subunits. The assembly of this structure requires two specialized chaperones, Atp11p and Atp12p, that bind transiently to α and β. In the absence of Atp11p and Atp12p, the hexamer is not formed, and α and β precipitate as large insoluble aggregates. An early model for the mechanism of chaperonemediated F1 assembly (Wang, Z. G., Sheluho, D., Gatti, D. L., and Ackerman, S. H. (2000) EMBO J. 19, 1486-1493) hypothesized that the chaperones themselves look very much like the α and β subunits, and proposed an exchange of Atp11p for α and of Atp12p for β; the driving force for the exchange was expected to be a higher affinity of α and β for each other than for the respective chaperone partners. One important feature of this model was the prediction that as long as Atp11p is bound to β and Atp12p is bound to α, the two F1 subunits cannot interact at either the catalytic site or the noncatalytic site interface. Here we present the structures of Atp11p from Candida glabrata and Atp12p from Paracoccus denitrificans, and we show that some features of the Wang model are correct, namely that binding of the chaperones to α and β prevents further interactions between these F1 subunits. However, Atp11p and Atp12p do not resemble α or β, and it is instead the F1 γ subunit that initiates the release of the chaperones from α and β and their further assembly into the mature complex.
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U2 - 10.1074/jbc.M109.002568
DO - 10.1074/jbc.M109.002568
M3 - Article
C2 - 19383603
AN - SCOPUS:67650517845
VL - 284
SP - 17138
EP - 17146
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 25
ER -