title: Human 3-alpha hydroxysteroid dehydrogenase type 3 (3α-HSD3): the V54L mutation restricting the steroid alternative binding and enhancing the 20α-HSD activity.
abstract: Human 3-alpha hydroxysteroid dehydrogenase type 3 (3α-HSD3) has an essential role in the inactivation of 5α-dihydrotestosterone (DHT). Notably, human 3α-HSD3 shares 97.8% sequence identity with human 20-alpha hydroxysteroid dehydrogenase (20α-HSD) and there is only one amino acid difference (residue 54) that is located in their steroid binding pockets. However, 20α-HSD displays a distinctive ability in transforming progesterone to 20α-hydroxy-progesterone (20α-OHProg). In this study, to understand the role of residue 54 in the steroid binding and discrimination, the V54L mutation in human 3α-HSD3 has been created. We have solved two crystal structures of the 3α-HSD3·NADP(+)·Progesterone complex and the 3α-HSD3 V54L·NADP(+)·progesterone complex. Interestingly, progesterone adopts two different binding modes to form complexes within the wild type enzyme, with one binding mode similar to the orientation of a bile acid (ursodeoxycholate) in the reported ternary complex of human 3α-HSD3·NADP(+)·ursodeoxycholate and the other binding mode resembling the orientation of 20α-OHProg in the ternary complex of human 20α-HSD·NADP(+)·20α-OHProg. However, the V54L mutation directly restricts the steroid binding modes to a unique one, which resembles the orientation of 20α-OHProg within human 20α-HSD. Furthermore, the kinetic study has been carried out. The results show that the V54L mutation significantly decreases the 3α-HSD activity for the reduction of DHT, while this mutation enhances the 20α-HSD activity to convert progesterone.
authors.affiliation: Laboratory of Molecular Endocrinology and Oncology, Centre Hospitalier Universitaire (CHU) de Quebec Research Center (CHUL) and Laval University, Québec City, Québec G1V4G2, Canada; Key Laboratory for Space Bioscience & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Laboratory of Molecular Endocrinology and Oncology, Centre Hospitalier Universitaire (CHU) de Quebec Research Center (CHUL) and Laval University, Québec City, Québec G1V4G2, Canada.
authors.forename: Dao-Wei
authors.initials: DW
authors.lastname: Zhu
authors.affiliation: School of Life Sciences, Fudan University, Shanghai 200433, PR China.
authors.forename: Xiao-Jian
authors.initials: XJ
authors.lastname: Hu
authors.affiliation: Laboratory of Molecular Endocrinology and Oncology, Centre Hospitalier Universitaire (CHU) de Quebec Research Center (CHUL) and Laval University, Québec City, Québec G1V4G2, Canada.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhou
authors.affiliation: Key Laboratory for Space Bioscience & Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Shang
authors.affiliation: Laboratory of Molecular Endocrinology and Oncology, Centre Hospitalier Universitaire (CHU) de Quebec Research Center (CHUL) and Laval University, Québec City, Québec G1V4G2, Canada; WHO Collaborating Center for Research in Human Reproductive Health, Shanghai 200031, PR China. Electronic address: sxlin@crchul.ulaval.ca.
authors.forename: Sheng-Xiang
authors.initials: SX
authors.lastname: Lin
mesh_terms: D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D013196:Dihydrotestosterone / Q000737:chemistry; D006801:Humans; D006860:Hydrogen Bonding; D006913:Hydroxysteroid Dehydrogenases / Q000737:chemistry* / Q000235:genetics; D007700:Kinetics; D008958:Models, Molecular; D020125:Mutation, Missense; D009249:NADP / Q000737:chemistry; D010084:Oxidation-Reduction; D011374:Progesterone / Q000737:chemistry; D011485:Protein Binding; D017433:Protein Structure, Secondary; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)
chemical_list: D013196:Dihydrotestosterone; D006913:Hydroxysteroid Dehydrogenases; D009249:NADP; D011374:Progesterone; C435496:AKR1C2 protein, human; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)
keywords: 20α-HSD; 3-Alpha hydroxysteroid dehydrogenase; AKR1C2; Crystal structure; Kinetics; Mutation