Regulation of iron-sulphur cluster homeostasis through transcriptional control of the Isc pathway by [2Fe-2S]-IscR in Escherichia coli.

ABSTRACT: Fe-S clusters are essential across the biological world, yet how cells regulate expression of Fe-S cluster biogenesis pathways to cope with changes in Fe-S cluster demand is not well understood. Here, we describe the mechanism by which IscR, a [2Fe-2S] cluster-containing regulator of Escherichia coli, adjusts the synthesis of the Isc Fe-S biogenesis pathway to maintain Fe-S homeostasis. Our data indicate that a negative feedback loop operates to repress transcription of the iscRSUA-hscBA-fdx operon, encoding IscR and the Isc machinery, through binding of [2Fe-2S]-IscR to two upstream binding sites. IscR was shown to require primarily the Isc pathway for synthesis of its Fe-S cluster, providing a link between IscR activity and demands for Fe-S clusters through the levels of the Isc system.

SUBMITTER: Giel JL 

PROVIDER: S-EPMC4108476 | biostudies-literature | 2013 Feb

REPOSITORIES: biostudies-literature