PMID: 25195888

Authors:

Roret T, Pegeot H, Couturier J, Mulliert G, Rouhier N, Didierjean C

Title:

X-ray structures of Nfs2, the plastidial cysteine desulfurase from Arabidopsis thaliana.

Journal:

Acta Crystallogr F Struct Biol Commun. 2014 Sep 1;70(Pt 9):1180-5. doi:, 10.1107/S2053230X14017026. Epub 2014 Aug 29.

Abstract:

The chloroplastic Arabidopsis thaliana Nfs2 (AtNfs2) is a group II pyridoxal 5'-phosphate-dependent cysteine desulfurase that is involved in the initial steps of iron-sulfur cluster biogenesis. The group II cysteine desulfurases require the presence of sulfurtransferases such as SufE proteins for optimal activity. Compared with group I cysteine desulfurases, proteins of this group contains a smaller extended lobe harbouring the catalytic cysteine and have a beta-hairpin constraining the active site. Here, two crystal structures of AtNfs2 are reported: a wild-type form with the catalytic cysteine in a persulfide-intermediate state and a C384S variant mimicking the resting state of the enzyme. In both structures the well conserved Lys241 covalently binds pyridoxal 5'-phosphate, forming an internal aldimine. Based on available homologous bacterial complexes, a model of a complex between AtNfs2 and the SufE domain of its biological partner AtSufE1 is proposed, revealing the nature of the binding sites.