The crystal structure of TrxA(CACA): Insights into the formation of a [2Fe-2S] iron-sulfur cluster in an Escherichia coli thioredoxin mutant.

ABSTRACT: Escherichia coli thioredoxin is a small monomeric protein that reduces disulfide bonds in cytoplasmic proteins. Two cysteine residues present in a conserved CGPC motif are essential for this activity. Recently, we identified mutations of this motif that changed thioredoxin into a homodimer bridged by a [2Fe-2S] iron-sulfur cluster. When exported to the periplasm, these thioredoxin mutants could restore disulfide bond formation in strains lacking the entire periplasmic oxidative pathway. Essential for the assembly of the iron-sulfur was an additional cysteine that replaced the proline at position three of the CGPC motif. We solved the crystalline structure at 2.3 Angstroms for one of these variants, TrxA(CACA). The mutant protein crystallized as a dimer in which the iron-sulfur cluster is r

SUBMITTER: Collet JF 

PROVIDER: S-EPMC2253358 | biostudies-literature | 2005 Jul

REPOSITORIES: biostudies-literature