9vii

Crystal structure of fused glycerol dehydratase A177M variant

spinqualitylabelsall models 9vii, resolution 3.56Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 9vii is a 8 chain structure with sequence from Klebsiella pneumoniae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.56Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q59476_KLEPN O08505_KLEPN Publication Abstract from PubMed Glycerol dehydratase (GDHt) enables bioconversion of glycerol to valuable chemicals, but its industrial use is hindered by rapid loss of the adenosylcobalamin (AdoCbl) cofactor (coenzyme B(12)) through both oxygen- and mechanism-based inactivation. To overcome this limitation, we reinforced the AdoCbl-binding interface of Klebsiella pneumoniae GDHt by fusing its alpha and beta subunits with a five-residue linker (fGDHt) and then introducing interface mutations. Fusion alone doubled the oxygen-inactivation half-life without affecting catalytic efficiency. Structural and computational analyses of interface residues, followed by experimental screening, yielded three stabilizing substitutions-alpha-A177M, beta-L113W, and beta-M158W. Pairwise combinations of these mutations yielded double variants whose oxygen-inactivation half-lives increased by up to 24-fold. Enzyme-coupled reactions to convert glycerol into 3-hydroxypropionic acid (3-HP) confirmed that engineered fGDHt variants maintained catalytic activity for longer periods, implying protection against both inactivation modes. In recombinant Escherichia coli strains producing 3-HP, the alpha-A177M/beta-M158W variant matched wild-type titers while operating with 25-fold less AdoCbl. Crystal structures reveal that the mutations tighten inter-subunit packing and, in the case of alpha-A177M, partly occlude an O(2)-access tunnel to the cofactor. These results have established alpha-beta interface engineering as a strategy for engineering more robust GDHts. Engineering the alpha- and beta-subunit interface of a coenzyme B(12)-dependent glycerol dehydratase for enhancing its resistance to inactivation.,Na CY, Nasir A, Park R, Yeon YJ, Baek SH, Park S, Park YS, Seo MD, Yoo TH Bioresour Technol. 2026 Feb;442:133733. doi: 10.1016/j.biortech.2025.133733. Epub , 2025 Nov 28. PMID:41319883 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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