Format

Send to

Choose Destination
J Am Chem Soc. 2002 Jul 31;124(30):8774-5.

Iron-sulfur cluster biosynthesis: characterization of iron nucleation sites for assembly of the [2Fe-2S]2+ cluster core in IscU proteins.

Author information

1
Evans Laboratory of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA.

Abstract

ISU (eukaryotes) and IscU (prokaryotes) are a homologous family of proteins that appear to provide a platform for assembly of [2Fe-2S] centers prior to delivery to a target apoprotein. The intermediate [2Fe-2S] IscU-bound cluster is formed by delivery of iron and sulfur to the apo-IscU, with the latter delivered through an IscS-mediated reaction. The identity of the iron donor is not yet established. In this report we characterize iron-binding sites on IscU that appear to nucleate [2Fe-2S] cluster assembly. This iron-bound form of IscU is shown to be viable for subsequent IscS-mediated assembly of holo-IscU. Following on recent reports, we demonstrate the persulfide form of IscU to be a dead-end complex that is incapable of forming holoprotein after addition of ferrous or ferric ion. The latter observation reflects the low binding affinity of persulfido IscU for iron ion.

PMID:
12137512
DOI:
10.1021/ja0264596
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for American Chemical Society
Loading ...
Support Center