9D7J

Clostridium acetobutylicum alcohol dehydrogenase bound to NADP+

Summary for 9D7J

• Entry DOI: 10.2210/pdb9d7j/pdb
• Descriptor: Oxidoreductase, NADP NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE, 1,2-ETHANEDIOL, ... (4 entities in total)
• Functional Keywords: alcohol dehydrogenase, loop disorder, oxidoreductase
• Biological source: Clostridium acetobutylicum
• Total number of polymer chains: 2
• Total formula weight: 63418.10

Authors

Madzelan, P.,Wilson, M.A. (deposition date: 2024-08-16, release date: 2025-07-02, Last modification date: 2025-09-10)

Primary citation

Kudalkar, G.P.,Leidner, F.,Kumar, N.,Hass, J.L.,Madzelan, P.,Powell, D.R.,Day, V.W.,Magueres, P.L.,Ferrara, J.D.,Daniels, L.M.,Yamano, A.,Ito, S.,Niu, W.,Grubmuller, H.,Wilson, M.A.,Berkowitz, D.B.
Is a Malleable Active Site Loop the Key to High Substrate Promiscuity? Hybrid, Biocatalytic Route to Structurally Diverse Taxoid Side Chains with Remarkable Dual Stereocontrol.
Angew.Chem.Int.Ed.Engl., 64:e202510889-e202510889, 2025

PubMed Abstract: These studies reveal the first structure of Clostridium acetobutylicum alcohol dehydrogenase (CaADH), a protein exhibiting remarkable substrate promiscuity and stereochemical fidelity. The CaADH enzyme is utilized here for synthesizing 20 potential aryl isoserine side chains for the Taxotere family of tubulin-binding chemotherapeutics. The approach involves dynamic reductive kinetic resolution (DYRKR) upon the corresponding α-chloro-β-keto esters, showing high D-syn stereoselectivity, including those leading to the clinically relevant milataxel (Ar = 2-furyl) and simotaxel (Ar = 2-thienyl) side chains. Furthermore, various cross-coupling chemistries performed on the p-bromophenyl isoserine side chain significantly enhance the structural diversity of the taxoid side chain library obtained (16 additional taxoid side chains). The CaADH structure is notable: (i) the nicotinamide cofactor is bound in an anti-conformation, with the amide carbonyl occupying the ketone binding pocket, and (ii) a flexible loop near the active site likely contributes to the remarkable substrate promiscuity observed in CaADH. We present our perspective on the dynamic nature of the CaADH active site through molecular dynamics simulation, proposing a halogen bonding model as a potential mechanism for the remarkable selectivity for an (S)-configured C─Cl bond, in addition to the D-facial selectivity, demonstrated across 20 diverse substrates by this remarkable short-chain dehydrogenase enzyme.

PubMed: 40537411
DOI: 10.1002/anie.202510889

Experimental method

X-RAY DIFFRACTION (1.39 Å)