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Updated: Jan 30, 2026
Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092
Published on: October 2, 2017
Crystal structure and biochemical characterization of malate dehydrogenase from Metallosphaera sedula
Donghoon Lee1, Jiyeon Hong1, Kyung-Jin Kim1
1School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu, 702-701, Republic of Korea; KNU Institute for Microorganisms, Kyungpook National University, Daegu, 41566, Republic of Korea.
Abstract:
Metallosphaera sedula is a thermoacidophilic autotrophic archaeon and known to utilize the 3-hydroxypropionate/4-hydroxybutyrate cycle (3-HP/4-HB cycle) as a carbon fixation pathway. The 3-HP/4-HB cycle in M. sedula is associated with central metabolism, and malate dehydrogenase (MDH) is an enzyme involved in the central metabolism that converts malate to oxaloacetate. To elucidate the enzymatic properties of MDH from M. sedula (MsMDH), we determined the crystal structure of MsMDH as a complex with NAD+ and a ternary complex with malate and NAD+. Based on its complex structures and biochemical experiments, we observed that MsMDH can utilize both NAD+ and NADP+ as a cofactor. In addition, we revealed that MsMDH shows a conformational change at the active site upon substrate binding. Based on the comparison with other MDHs, we revealed that MsMDH was distinguished from general MDHs due to a Lys80 residue, and this difference is likely to influence the unique cofactor specificity of MsMDH.
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