3G1Q

Crystal structure of sterol 14-alpha demethylase (CYP51) from Trypanosoma brucei in ligand free state

Summary for 3G1Q

• Entry DOI: 10.2210/pdb3g1q/pdb
• Descriptor: Sterol 14-alpha-demethylase, PROTOPORPHYRIN IX CONTAINING FE (3 entities in total)
• Functional Keywords: sterol 14-alpha demethylase, cyp51, cytochrome p450, heme, oxidoreductase, monooxygenase, membrane protein, sterol biosynthesis
• Biological source: Trypanosoma brucei
• Total number of polymer chains: 4
• Total formula weight: 206370.56

Authors

Lepesheva, G.I.,Hargrove, T.Y.,Harp, J.,Wawrzak, Z.,Waterman, M.R.,Park, H. (deposition date: 2009-01-30, release date: 2009-10-06, Last modification date: 2023-09-06)

Primary citation

Lepesheva, G.I.,Park, H.W.,Hargrove, T.Y.,Vanhollebeke, B.,Wawrzak, Z.,Harp, J.M.,Sundaramoorthy, M.,Nes, W.D.,Pays, E.,Chaudhuri, M.,Villalta, F.,Waterman, M.R.
Crystal structures of Trypanosoma brucei sterol 14alpha-demethylase and implications for selective treatment of human infections.
J.Biol.Chem., 285:1773-1780, 2010

PubMed Abstract: Sterol 14alpha-demethylase (14DM, the CYP51 family of cytochrome P450) is an essential enzyme in sterol biosynthesis in eukaryotes. It serves as a major drug target for fungal diseases and can potentially become a target for treatment of human infections with protozoa. Here we present 1.9 A resolution crystal structures of 14DM from the protozoan pathogen Trypanosoma brucei, ligand-free and complexed with a strong chemically selected inhibitor N-1-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)ethyl)-4-(5-phenyl-1,3,4-oxadi-azol-2-yl)benzamide that we previously found to produce potent antiparasitic effects in Trypanosomatidae. This is the first structure of a eukaryotic microsomal 14DM that acts on sterol biosynthesis, and it differs profoundly from that of the water-soluble CYP51 family member from Mycobacterium tuberculosis, both in organization of the active site cavity and in the substrate access channel location. Inhibitor binding does not cause large scale conformational rearrangements, yet induces unanticipated local alterations in the active site, including formation of a hydrogen bond network that connects, via the inhibitor amide group fragment, two remote functionally essential protein segments and alters the heme environment. The inhibitor binding mode provides a possible explanation for both its functionally irreversible effect on the enzyme activity and its selectivity toward the 14DM from human pathogens versus the human 14DM ortholog. The structures shed new light on 14DM functional conservation and open an excellent opportunity for directed design of novel antiparasitic drugs.

PubMed: 19923211
DOI: 10.1074/jbc.M109.067470

Experimental method

X-RAY DIFFRACTION (1.89 Å)