8I5Z

LDH Mutant P101Q-(An unexpected single-point mutation triggers the unleashing of catalytic potential of a NADH-dependent dehydrogenase)

Summary for 8I5Z

• Entry DOI: 10.2210/pdb8i5z/pdb
• Descriptor: D-isomer specific 2-hydroxyacid dehydrogenase NAD-binding protein (2 entities in total)
• Functional Keywords: ldh, biosynthetic protein
• Biological source: Thermodesulfatator indicus DSM 15286
• Total number of polymer chains: 4
• Total formula weight: 150845.19

Authors

Liu, J.Q. (deposition date: 2023-01-26, release date: 2023-09-06, Last modification date: 2024-03-20)

Primary citation

Liu, J.,Liu, G.,Han, X.,Tao, F.,Xu, P.
Characterization of the Pro101Gln mutation that enhances the catalytic performance of T. indicus NADH-dependent d-lactate dehydrogenase.
Structure, 31:1616-1628.e3, 2023

PubMed Abstract: NADH-dependent d-lactate dehydrogenases (d-LDH) are important for the industrial production of d-lactic acid. Here, we identify and characterize an improved d-lactate dehydrogenase mutant (d-LDH1) that contains the Pro101Gln mutation. The specific enzyme activities of d-LDH1 toward pyruvate and NADH are 21.8- and 11.0-fold greater compared to the wild-type enzyme. We determined the crystal structure of Apo-d-LDH1 at 2.65 Å resolution. Based on our structural analysis and docking studies, we explain the differences in activity with an altered binding conformation of NADH in d-LDH1. The role of the conserved residue Pro101 in d-LDH was further probed in site-directed mutagenesis experiments. We introduced d-LDH1 into Bacillus licheniformis yielding a d-lactic acid production of 145.9 g L within 60 h at 50°C, which was three times higher than that of the wild-type enzyme. The discovery of d-LDH1 will pave the way for the efficient production of d-lactic acid by thermophilic bacteria.

PubMed: 37729918
DOI: 10.1016/j.str.2023.08.019

Experimental method

X-RAY DIFFRACTION (2.65 Å)