David P. Barondeau

TL;DR: The 1.30 A resolution crystal structure of nickel superoxide dismutase (NiSOD) identifies a novel SOD fold, assembly, and Ni active site that provides almost all interactions critical for metal binding and catalysis, and thus will likely be diagnostic of NiSODs.

TL;DR: In vitro evidence is provided that human frataxin binds to a Nfs1, Isd11, and Isu2 complex to generate the four-component core machinery for Fe-S cluster biosynthesis, and a model in which cellular fr ataxin levels regulate human Fe- S cluster biosynthetic activities is proposed that has implications for mitochondrial dysfunction, oxidative stress response, and both neurodegenerative and cardiovascular disease.

TL;DR: The protein architecture contains a dramatic ≈80° bend in the central helix, which focuses distortions at G67 to promote ring formation from amino acids S65, Y66, and G67, and this leads directly to a conjugation-trapping mechanism, in which a thermodynamically unfavorable cyclization reaction is coupled to an electronic conjugations trapping step, to drive chromophore maturation.

TL;DR: Radiolabeling experiments indicate FXN accelerates the accumulation of sulfur on ISCU2 and that the resulting persulfide species is viable in the subsequent synthesis of Fe–S clusters, which cannot be fully explained by the hypothesis that FXN functions as an iron donor for Fe-S cluster biosynthesis.

TL;DR: The unexpected architecture for the SDA complex provides a framework for understanding interactions with acceptor proteins for sulfur-containing biosynthetic pathways, elucidating mechanistic details of eukaryotic Fe–sulfur cluster biosynthesis, and clarifying how defects in Fe–S cluster assembly lead to diseases such as Friedreich’s ataxia.