1. Characterization of cold-tolerant trehalose-6-phosphate synthase from the deep-sea bacterium Microbacterium sediminis YLB-01.
- Author
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Tang X, Yi Z, Xu X, Xu R, Huang P, and Yu L
- Subjects
- Amino Acid Sequence, Barium chemistry, Cobalt chemistry, Enzyme Stability, Escherichia coli genetics, Escherichia coli metabolism, Geologic Sediments microbiology, Hydrogen Bonding, Hydrogen-Ion Concentration, Indian Ocean, Ions chemistry, Kinetics, Magnesium chemistry, Microbacterium enzymology, Microbacterium genetics, Molecular Dynamics Simulation, Phylogeny, Protein Structure, Secondary, Protein Structure, Tertiary, Recombinant Proteins, Cold Temperature, Glucosyltransferases chemistry, Glucosyltransferases genetics
- Abstract
A gene encoding the enzyme trehalose-6-phosphate synthase (TPS), which is part of the TPS trehalose synthesis pathway, was cloned from the deep-sea psychrotolerant bacterium Microbacterium sediminis YLB-01 and expressed in Escherichia coli BL21. The exogenously expressed TPS exhibited highest similarity (80.93% identity) to Microbacterium sp. TPS. The purified recombinant TPS was cold-tolerant, with low thermostability. The optimum temperature for TPS activity was 40°C, and the enzyme retained 72.6% of its maximal activity at 4°C. The optimum pH was 7.5. TPS activity was cation-dependent, with Mg
2+ , Co2+ , or Ba2+ being essential for maximum activity. The kinetic constants of the recombinant TPS reaction rates confirmed that it was cold-tolerant. Molecular dynamics analysis showed that TPS was more flexible (0.8741Å) at 4°C than 1GZ5, its homolog in the mesophilic bacterium E. coli , and superposition of the 3D enzyme structures supported this.- Published
- 2020
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