 peroxisome proliferator activated receptor- ( ppar ) regulates metabolic homeostasis and adipocyte differentiation , and it is activated by oxidized and nitrated fatty acids . here 
 we report the crystal structure of the ppar ligand binding domain bound to nitrated linoleic acid , a potent endogenous ligand of ppar. structural and functional studies of receptor - ligand interactions reveal the molecular basis of ppar discrimination of various naturally occurring fatty acid derivatives . 
Supplementary Material