Structural basis of stereospecific reduction by quinuclidinone reductase

• Published in: AMB Express Vol. 4; no. 1; p. 6
• Main Authors: Takeshita, Daijiro, Kataoka, Michihiko, Miyakawa, Takuya, Miyazono, Ken-ichi, Kumashiro, Shoko, Nagai, Takahiro, Urano, Nobuyuki, Uzura, Atsuko, Nagata, Koji, Shimizu, Sakayu, Tanokura, Masaru
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 07.02.2014; Springer Nature B.V; BioMed Central Ltd; Springer
• Subjects: Biomedical and Life Sciences; Biotechnology; Life Sciences; Microbial Genetics and Genomics; Microbiology; Original; Original Article; Rhodotorula rubra; Asymmetric reduction; (; 3-quinuclidinol; NADPH-dependent enzyme; 3-Quinuclidinone reductase; Crystal structure
• ISSN: 2191-0855; 2191-0855
• DOI: 10.1186/2191-0855-4-6

Chiral molecule ( R )-3-quinuclidinol, a valuable compound for the production of various pharmaceuticals, is efficiently synthesized from 3-quinuclidinone by using NADPH-dependent 3-quinuclidinone reductase (RrQR) from Rhodotorula rubra . Here, we report the crystal structure of RrQR and the structure-based mutational analysis. The enzyme forms a tetramer, in which the core of each protomer exhibits the α/β Rossmann fold and contains one molecule of NADPH, whereas the characteristic substructures of a small lobe and a variable loop are localized around the substrate-binding site. Modeling and mutation analyses of the catalytic site indicated that the hydrophobicity of two residues, I167 and F212, determines the substrate-binding orientation as well as the substrate-binding affinity. Our results revealed that the characteristic substrate-binding pocket composed of hydrophobic amino acid residues ensures substrate docking for the stereospecific reaction of RrQR in spite of its loose interaction with the substrate.