Functional implications of the interaction between HscB and IscU in the biosynthesis of FeS clusters

Verfasser / Beitragende:
[Stefania Iametti, Alberto Barbiroli, Francesco Bonomi]
Ort, Verlag, Jahr:
2015
Enthalten in:
JBIC Journal of Biological Inorganic Chemistry, 20/6(2015-09-01), 1039-1048
Format:
Artikel (online)
ID: 605507104
LEADER caa a22 4500
001 605507104
003 CHVBK
005 20210128100630.0
007 cr unu---uuuuu
008 210128e20150901xx s 000 0 eng
024 7 0 |a 10.1007/s00775-015-1285-z  |2 doi 
035 |a (NATIONALLICENCE)springer-10.1007/s00775-015-1285-z 
245 0 0 |a Functional implications of the interaction between HscB and IscU in the biosynthesis of FeS clusters  |h [Elektronische Daten]  |c [Stefania Iametti, Alberto Barbiroli, Francesco Bonomi] 
520 3 |a In bacteria, HscB is the cochaperone of HscA in modulating the transfer of 2Fe2S clusters from a cluster-loaded form of the scaffold protein IscU to acceptor apoproteins. HscB binding to the IscU apoform (apoIscU) reportedly impairs the structural flexibility of apoIscU, but the effects of HscB on cluster formation on IscU have never been assessed. We report that presence of HscB impaired the rate—but not the equilibrium—of the appearance of the distinctive circular dichroism signals associated with formation of a stable 2Fe-2S cluster on IscU in reconstitution experiments. This impairment: (1) was independent of the source of cluster sulfide; (2) was not observed for HscB mutants unable to bind IscU; (3) implied formation of a 1/1 HscB/IscU complex; (4) was not observed for a D39A mutant of IscU, with a much more rigid structure than wt IscU. The cluster species assembled on IscU in the presence of HscB were transferred to apoferredoxin at a slower rate than those formed in the absence of HscB, unless ATP and HscA were also present. At contrast, HscB was found to improve the "catalytic” function of IscU with respect to cluster assembly in the presence of a large apoferredoxin excess. Thus, the HscB/IscU interaction may modulate formation and transfer of FeS clusters by accelerating cluster biosynthesis when appropriate target apoproteins are abundant or by slowing it down when the rate of apoprotein synthesis is slow, and cluster-loaded IscU is more likely to play a role as a "FeS storage” protein. Graphical Abstract: 
540 |a SBIC, 2015 
690 7 |a Iron-sulfur cluster biosynthesis  |2 nationallicence 
690 7 |a Molecular chaperones  |2 nationallicence 
690 7 |a Scaffold proteins  |2 nationallicence 
690 7 |a Protein-protein interactions  |2 nationallicence 
690 7 |a CD : Circular dichroism  |2 nationallicence 
690 7 |a TD buffer : 0.1M Tris-HCl, pH 8.0, 5mM dithiothreitol  |2 nationallicence 
690 7 |a TDMK buffer : 0.1M Tris-HCl, pH 8.0, 5mM dithiothreitol, 10mM MgCl2, 150mM KCl  |2 nationallicence 
700 1 |a Iametti  |D Stefania  |u Section of Chemical and Biomolecular Sciences, DeFENS, University of Milan, Via Celoria 2, 20133, Milan, Italy  |4 aut 
700 1 |a Barbiroli  |D Alberto  |u Section of Chemical and Biomolecular Sciences, DeFENS, University of Milan, Via Celoria 2, 20133, Milan, Italy  |4 aut 
700 1 |a Bonomi  |D Francesco  |u Section of Chemical and Biomolecular Sciences, DeFENS, University of Milan, Via Celoria 2, 20133, Milan, Italy  |4 aut 
773 0 |t JBIC Journal of Biological Inorganic Chemistry  |d Springer Berlin Heidelberg  |g 20/6(2015-09-01), 1039-1048  |x 0949-8257  |q 20:6<1039  |1 2015  |2 20  |o 775 
856 4 0 |u https://doi.org/10.1007/s00775-015-1285-z  |q text/html  |z Onlinezugriff via DOI 
898 |a BK010053  |b XK010053  |c XK010000 
900 7 |a Metadata rights reserved  |b Springer special CC-BY-NC licence  |2 nationallicence 
908 |D 1  |a research-article  |2 jats 
949 |B NATIONALLICENCE  |F NATIONALLICENCE  |b NL-springer 
950 |B NATIONALLICENCE  |P 856  |E 40  |u https://doi.org/10.1007/s00775-015-1285-z  |q text/html  |z Onlinezugriff via DOI 
950 |B NATIONALLICENCE  |P 700  |E 1-  |a Iametti  |D Stefania  |u Section of Chemical and Biomolecular Sciences, DeFENS, University of Milan, Via Celoria 2, 20133, Milan, Italy  |4 aut 
950 |B NATIONALLICENCE  |P 700  |E 1-  |a Barbiroli  |D Alberto  |u Section of Chemical and Biomolecular Sciences, DeFENS, University of Milan, Via Celoria 2, 20133, Milan, Italy  |4 aut 
950 |B NATIONALLICENCE  |P 700  |E 1-  |a Bonomi  |D Francesco  |u Section of Chemical and Biomolecular Sciences, DeFENS, University of Milan, Via Celoria 2, 20133, Milan, Italy  |4 aut 
950 |B NATIONALLICENCE  |P 773  |E 0-  |t JBIC Journal of Biological Inorganic Chemistry  |d Springer Berlin Heidelberg  |g 20/6(2015-09-01), 1039-1048  |x 0949-8257  |q 20:6<1039  |1 2015  |2 20  |o 775