IscU functions as a scaffold for Fe-S cluster assembly and transfer, and is known to be a substrate protein for molecular chaperones. Kinetic studies of Fe-S cluster transfer from holo IscU to apo Fd in the presence of chaperone DnaK demonstrate an inhibitory effect on the rate of Fe-S cluster transfer from IscU. Binding of DnaK reduces the rate of formation of the IscU−Fd complex (greater than 8-fold), but has little influence on the intrinsic rate of iron−sulfur cluster transfer to apo Fd. Apparently the molecular chaperone DnaK does not facilitate the process of Fe-S cluster transfer from IscU. Rather, DnaK has a modest influence on the stability of the IscU-bound Fe-S cluster that may reflect a more important role in promoting cluster assembly. In accord with prior observations the cochaperone DnaJ stimulates the ATPase activity of DnaK, but has a minimal influence on IscU cluster transfer activity, either alone or in concert with DnaK.
Iron-sulfur cluster biosynthesis. Molecular chaperone DnaK promotes IscU-bound [2Fe-2S] cluster stability and inhibits cluster transfer activity / S. P., Wu; Mansy, Sheref Samir; J. A., Cowan. - In: BIOCHEMISTRY. - ISSN 0006-2960. - STAMPA. - 44:11(2005), pp. 4284-4293. [10.1021/bi0483007]
Iron-sulfur cluster biosynthesis. Molecular chaperone DnaK promotes IscU-bound [2Fe-2S] cluster stability and inhibits cluster transfer activity.
Mansy, Sheref Samir;
2005-01-01
Abstract
IscU functions as a scaffold for Fe-S cluster assembly and transfer, and is known to be a substrate protein for molecular chaperones. Kinetic studies of Fe-S cluster transfer from holo IscU to apo Fd in the presence of chaperone DnaK demonstrate an inhibitory effect on the rate of Fe-S cluster transfer from IscU. Binding of DnaK reduces the rate of formation of the IscU−Fd complex (greater than 8-fold), but has little influence on the intrinsic rate of iron−sulfur cluster transfer to apo Fd. Apparently the molecular chaperone DnaK does not facilitate the process of Fe-S cluster transfer from IscU. Rather, DnaK has a modest influence on the stability of the IscU-bound Fe-S cluster that may reflect a more important role in promoting cluster assembly. In accord with prior observations the cochaperone DnaJ stimulates the ATPase activity of DnaK, but has a minimal influence on IscU cluster transfer activity, either alone or in concert with DnaK.File | Dimensione | Formato | |
---|---|---|---|
2005WuBiochem.pdf
Solo gestori archivio
Tipologia:
Versione editoriale (Publisher’s layout)
Licenza:
Tutti i diritti riservati (All rights reserved)
Dimensione
618.17 kB
Formato
Adobe PDF
|
618.17 kB | Adobe PDF | Visualizza/Apri |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione