8JG2
Crystal structure of a biosynthetic thiolase from Megasphaera hexanoica soaked with hexanoyl-CoA
Summary for 8JG2
| Entry DOI | 10.2210/pdb8jg2/pdb |
| Descriptor | Acetyl-CoA C-acetyltransferase, COENZYME A, ACETATE ION, ... (4 entities in total) |
| Functional Keywords | acetyl-coenzyme a c-acyltransferase, biosynthetic protein |
| Biological source | Megasphaera hexanoica |
| Total number of polymer chains | 2 |
| Total formula weight | 93836.61 |
| Authors | Kim, E.-J.,Seo, H.,Kim, K.-J. (deposition date: 2023-05-19, release date: 2024-05-08, Last modification date: 2025-11-19) |
| Primary citation | Jeon, B.S.,Kim, E.J.,Seo, H.,Kim, H.,Shin, S.,Schlaiss, C.,Angenent, L.T.,Kim, K.J.,Sang, B.I. Molecular Chain Elongation Mechanism for n-Caproate Biosynthesis by Megasphaera Hexanoica. Adv Sci, :e06069-e06069, 2025 Cited by PubMed Abstract: The microbial production of medium-chain carboxylates has attracted considerable interest owing to their potential applications in biofuels and specialty chemicals; however, the underlying biosynthetic mechanisms remain incompletely understood. The present study evaluates the medium-chain carboxylate-producing microbe Megaspahera hexanoica using genomic analysis, transcriptome analysis, and metabolic engineering. Additionally, the n-caproate synthesis pathway of M. hexanoica is characterized with fructose as an electron donor, and the substrate specificity of the respective proteins is evaluated by constructing an n-caproate biosynthetic pathway in Escherichia coli. Among all r-BOX or RBO genes, thl_1583, which encodes β-ketothiolase (MhTHL), is identified as the most critical enzyme for the carbon chain elongation mechanism in M. hexanoica. Therefore, MhTHL is compared with other well-studied β-ketothiolases (CkTHL from Clostridium kluyveri, ReBktB from Ralstonia eutropha (Cupriavidus necator), EcAtoB from E. coli, and CaTHL from C. acetobutylicum). MhTHL is found to exhibit the highest n-caproate production, as evidenced by the protein crystal structure of MhTHL. Structural comparisons with other thiolases show that MhTHL has a larger substrate-binding pocket than ReBktB. Thiolase mutants generated by site-directed mutagenesis reveal that two residues (Leu87 and Val351) are essential for determining the size of the substrate-binding pocket. PubMed: 40932660DOI: 10.1002/advs.202506069 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.64 Å) |
Structure validation
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