On the highly conserved Iron-Sulfur cluster assembly machinery (Presentación oral)

JUSTO OLMOS; MAURO BRINGAS; FRANCISCO VELAZQUEZ; ANA B. BENÍTEZ DOS SANTOS; SEBASTIÁN KLINKE; JAVIER SANTOS; MARÍA F. PIGNATARO; LAURA KAMENETZKY

Evento online

Jornada; Primeras Jornadas Virtuales de la Sociedad Argentina de Biofísica; 2020

Sociedad Argentina de Biofísica (SAB)

Numerous metabolic pathways depend on iron-sulfur clusters ([Fe-S]). We have explored the D. discoideum genome looking for genes corresponding to proteins that form the molecular machinery for Fe-S cluster biosynthesis. Based on the structure of the mammalian supercomplex and sequence conservation profiles, we inferred the full functionality of the amoeba machinery. In addition, we produced D. discoideum frataxin protein (DdFXN), the kinetic activator of this pathway. DdFXN is monomeric and compact. The secondary structure content calculated using the far-UV CD spectra was compatible with the data expected for the FXN fold. The near-UV CD spectra were compatible with the corresponding to a folded protein. On the other hand, DdFXN is less stable than that of human FXN. Based on structural models of DdFXN, we studied key residues involved in the interaction of DdFXN with the supercomplex and the effect of point mutations on the energetics. More than 10 residues involved in Friedreich´s Ataxia are conserved between the human and DdFXN forms, and a good correlation between the mutational effect on the energetics of both proteins was inferred, suggesting the existence of similar sequence/stability/function relationships. This information was integrated into an evolutionary context.