Related Experiment Video
Updated: Dec 13, 2025

Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks MOFs
Published on: January 17, 2020
Structural Characterization of an S-enantioselective Imine Reductase from Mycobacterium Smegmatis
Timo Meyer1, Nadine Zumbrägel2, Christina Geerds1
1Structural Biochemistry, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany.
Abstract:
NADPH-dependent imine reductases (IREDs) are enzymes capable of enantioselectively reducing imines to chiral secondary amines, which represent important building blocks in the chemical and pharmaceutical industry. Since their discovery in 2011, many previously unknown IREDs have been identified, biochemically and structurally characterized and categorized into families. However, the catalytic mechanism and guiding principles for substrate specificity and stereoselectivity remain disputed. Herein, we describe the crystal structure of S-IRED-Ms from Mycobacterium smegmatis together with its cofactor NADPH. S-IRED-Ms belongs to the S-enantioselective superfamily 3 (SFam3) and is the first IRED from SFam3 to be structurally described. The data presented provide further evidence for the overall high degree of structural conservation between different IREDs of various superfamilies. We discuss the role of Asp170 in catalysis and the importance of hydrophobic amino acids in the active site for stereospecificity. Moreover, a separate entrance to the active site, potentially functioning according to a gatekeeping mechanism regulating access and, therefore, substrate specificity is described.
Related Concept Videos
Aldehydes and Ketones with Amines: Imine and Enamine Formation Overview
Prochirality
Aldehydes and Ketones with Amines: Enamine Formation Mechanism
Chirality at Nitrogen, Phosphorus, and Sulfur
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
Preparation of Amines: Reductive Amination of Aldehydes and Ketones
Synthesis of α-Substituted Carbonyl Compounds: The Stork Enamine Reaction

![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)