Reactivity of nitric oxide with the [4Fe-4S] cluster of dihydroxyacid dehydratase from Escherichia coli.

ABSTRACT: Although the NO (nitric oxide)-mediated modification of iron-sulfur proteins has been well-documented in bacteria and mammalian cells, specific reactivity of NO with iron-sulfur proteins still remains elusive. In the present study, we report the first kinetic characterization of the reaction between NO and iron-sulfur clusters in protein using the Escherichia coli IlvD (dihydroxyacid dehydratase) [4Fe-4S] cluster as an example. Combining a sensitive NO electrode with EPR (electron paramagnetic resonance) spectroscopy and an enzyme activity assay, we demonstrate that NO is rapidly consumed by the IlvD [4Fe-4S] cluster with the concomitant formation of the IlvD-bound DNIC (dinitrosyl-iron complex) and inactivation of the enzyme activity under anaerobic conditions. The rate constant for the i

SUBMITTER: Duan X 

PROVIDER: S-EPMC2706667 | biostudies-literature | 2009 Feb

REPOSITORIES: biostudies-literature