Isovaleryl-CoA(coenzyme A)dehydrogenase(IVD)plays a pivotal role in the catabolism of leucine,converting isovaleryl-CoA to 3-methylcrotonyl-CoA.Dysfunction of IVD is linked to isovaleric acidemia(IVA),a rare metabolic...Isovaleryl-CoA(coenzyme A)dehydrogenase(IVD)plays a pivotal role in the catabolism of leucine,converting isovaleryl-CoA to 3-methylcrotonyl-CoA.Dysfunction of IVD is linked to isovaleric acidemia(IVA),a rare metabolic disorder characterized by the accumulation of toxic metabolites.In this study,we present the cryo-electron microscopy structures of human IVD,resolved both in its apo form and in complex with its substrates,isovaleryl-CoA and butyryl-CoA.Our findings reveal a tetrameric architecture with distinct substrate-binding pockets that facilitate the enzyme’s preference for short branched-chain acyl-CoAs.Key residues involved in FAD binding and substrate interaction were identified,elucidating the catalytic mechanism of IVD.Additionally,we investigated the impact of various disease-associated hotspot mutations derived from different regions,demonstrating their effects on enzyme stability and activity.Notably,mutations such as A314V,S281G/F382V,and E411K resulted in substantial loss of function,while others exhibited milder effects,which is consistent with our structural analyses.These insights enhance our understanding of IVD’s enzymatic properties and provide a foundation for developing targeted therapies for IVA.展开更多
基金supported by the National Key Research and Development Program of China(2022YFC2703100 and 2023YFC3605504)the Chinese Academy of Medical Sciences Initiative for Innovative Medicine(2021-I2M-1-003)+1 种基金the National High Level Hospital Clinical Research Funding(2022-PUMCH-D-002 and 2022-PUMCH-B-098)the National Natural Science Foundation of China(82225007,92149305,and 82030017).
文摘Isovaleryl-CoA(coenzyme A)dehydrogenase(IVD)plays a pivotal role in the catabolism of leucine,converting isovaleryl-CoA to 3-methylcrotonyl-CoA.Dysfunction of IVD is linked to isovaleric acidemia(IVA),a rare metabolic disorder characterized by the accumulation of toxic metabolites.In this study,we present the cryo-electron microscopy structures of human IVD,resolved both in its apo form and in complex with its substrates,isovaleryl-CoA and butyryl-CoA.Our findings reveal a tetrameric architecture with distinct substrate-binding pockets that facilitate the enzyme’s preference for short branched-chain acyl-CoAs.Key residues involved in FAD binding and substrate interaction were identified,elucidating the catalytic mechanism of IVD.Additionally,we investigated the impact of various disease-associated hotspot mutations derived from different regions,demonstrating their effects on enzyme stability and activity.Notably,mutations such as A314V,S281G/F382V,and E411K resulted in substantial loss of function,while others exhibited milder effects,which is consistent with our structural analyses.These insights enhance our understanding of IVD’s enzymatic properties and provide a foundation for developing targeted therapies for IVA.
