Download MendeleyStructural insights into the mechanism underlying the dual cofactor specificity of glyoxylate reductase from Acetobacter aceti in the beta-hydroxyacid dehydrogenase family.
Majumder, T.R., Yoshizawa, T., Inoue, M., Aono, R., Matsumura, H., Mihara, H.(2025) Biochim Biophys Acta Proteins Proteom 1873: 141051-141051
- PubMed: 39368682
- DOI: https://doi.org/10.1016/j.bbapap.2024.141051
- Primary Citation of Related Structures:
8Z0X, 8Z9F, 8Z9G - PubMed Abstract:
The β-hydroxyacid dehydrogenase family exhibits diverse cofactor preferences: some enzymes favor NAD, others favor NADP, and a subset can utilize both NAD and NADPH. Glyoxylate reductase from Acetobacter aceti JCM 20276 (AacGR) exhibits a dual cofactor specificity for NADPH and NADH in its catalytic reduction of glyoxylate to glycolate. In contrast to conventional cofactor-discriminating motifs, NRX and DXX, found in NADP- and NAD-specific enzymes, respectively, AacGR has a TPS motif in the equivalent position. Here we report X-ray crystallographic analysis of AacGR in its ligand-free form, and in complexes with NADPH and NADH, revealing critical interactions: Ser41 of the TPS motif interacted with the 2'-phosphate group of NADPH, while no analogous interaction occurred with the ribose hydroxy groups of NADH. Moreover, the TPS motif resided within a characteristic β-turn-like structure adjacent to a long flexible loop. Site-directed mutagenesis and kinetic analyses suggest that Ser41 facilitates NADPH binding, while the lack of a direct interaction of the TPS motif with NADH may allow for NADH utilization. The conformational dynamics of the TPS-containing β-turn-like structure along with the flexible loop likely govern the dual cofactor specificity and catalytic turnover of AacGR.
Organizational Affiliation:
College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577, Japan.
