7F8D

Malate Dehydrogenase from Geobacillus stearothermophilus (gs-MDH) G218Y mutant

Summary for 7F8D

• Entry DOI: 10.2210/pdb7f8d/pdb
• Descriptor: Malate dehydrogenase, NICOTINAMIDE-ADENINE-DINUCLEOTIDE (3 entities in total)
• Functional Keywords: malate dehydrogenase, oxidoreductase
• Biological source: Geobacillus stearothermophilus (Bacillus stearothermophilus)
• Total number of polymer chains: 4
• Total formula weight: 146807.44

Authors

Shimozawa, Y.,Himiyama, T.,Nakamura, T.,Nishiya, Y. (deposition date: 2021-07-02, release date: 2022-02-23, Last modification date: 2023-11-29)

Primary citation

Shimozawa, Y.,Himiyama, T.,Nakamura, T.,Nishiya, Y.
Increasing loop flexibility affords low-temperature adaptation of a moderate thermophilic malate dehydrogenase from Geobacillus stearothermophilus.
Protein Eng.Des.Sel., 34:-, 2021

PubMed Abstract: Malate dehydrogenase (MDH) catalyzes the reversible reduction of nicotinamide adenine dinucleotide from oxaloacetate to L-malate. MDH from moderate thermophilic Geobacillus stearothermophilus (gs-MDH) has high thermal stability and substrate specificity and is used as a diagnostic reagent. In this study, gs-MDH was engineered to increase its catalytic activity at low temperatures. Based on sequential and structural comparison with lactate dehydrogenase from G. stearothermophilus, we selected G218 as a mutation site to increase the loop flexibility pivotal for MDH catalysis. The G218 mutants showed significantly higher specific activities than the wild type at low temperatures and maintained thermal stability. The crystal structure of the G218Y mutant, which had the highest catalytic efficiency among all the G218 mutants, suggested that the flexibility of the mobile loop was successfully increased by the bulky side chain. Therefore, this study demonstrated the low-temperature adaptation of MDH by facilitating conformational changes during catalysis.

PubMed: 34850194
DOI: 10.1093/protein/gzab026

Experimental method

X-RAY DIFFRACTION (2.4 Å)