9PXQ

Crystal structure of bovine ALDH3A1 in complex with Canonical Redox Cofactors, NAD+

Summary for 9PXQ

• Entry DOI: 10.2210/pdb9pxq/pdb
• Descriptor: Aldehyde dehydrogenase, NICOTINAMIDE-ADENINE-DINUCLEOTIDE, GLYCEROL, ... (5 entities in total)
• Functional Keywords: aldehyde dehydrogenase, non-canonical redox cofactor, biomimetic nicotinamide coenzyme, nicotinamide mononucleotide, enzyme engineering, active site pre-organization, oxidoreductase
• Biological source: Bos taurus (domestic cattle)
• Total number of polymer chains: 2
• Total formula weight: 102681.96

Authors

Hsu, N.,Saleh, S.,Kim, J.,Li, H.,Qiao, F. (deposition date: 2025-08-06, release date: 2026-09-02, Last modification date: 2026-09-30)

Primary citation

Saleh, S.,Hsu, N.H.,Luu, E.,Martin, V.C.,Ng, H.J.C.,Black, W.B.,Zhang, S.,Kim, J.K.,Sankaran, B.,Tran, A.H.T.,Hayes, R.L.,Siegel, J.B.,Qiao, F.,Li, H.
A sequence motif enables widespread use of noncanonical redox cofactors in natural enzymes.
Nat.Chem.Biol., 2026

PubMed Abstract: Noncanonical redox cofactors (NRCs) are low-cost alternatives to the natural redox cofactors nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP) for biomanufacturing, offering exquisite electron-delivery control, yet their adoption is limited by the scarcity of compatible enzymes. Screening the aldehyde dehydrogenase (ALDH) family, we identified a conserved RH/QxxR motif that enables widespread NRC activity among natural enzymes. Bos taurus ALDH3a1 exhibits unprecedented turnover with nicotinamide mononucleotide (NMN), with k values exceeding NAD and surpassing most engineered NRC-active enzymes by 10-10-fold. Structural analyses reveal that this motif reinforces cofactor positioning and preorganizes the active site independently of the NAD adenosine monophosphate moiety. This motif supports activity across simple-synthetic NRCs such as 1-(2-carbamoylmethyl)nicotinamide and, when introduced into diverse ALDH scaffolds, enhances NMN activity up to 60-fold. These findings elucidate nature's solution to engineering NRC-active enzymes and offer a blueprint to mine latent evolutionary plasticity in natural enzymes that serve as superior engineering starting points.

PubMed: 42717052
DOI: 10.1038/s41589-026-02315-w

Experimental method

X-RAY DIFFRACTION (1.46 Å)