Publications by authors named "Yewon Nam"

Adenosylcobinamide kinase/adenosylcobinamide phosphate guanylyltransferase (CobU) is one of the key enzymes that participate in the biosynthesis of cobalamin, specifically lining the lower ligand 5,6-dimethylbenzimidazole in the α-position of cyclic tetrapyrrolidine. During this process, CobU exhibits two distinct activities: kinase and nucleotidyl transferase, using two nucleoside triphosphates. A structural study of CobU from Salmonella typhimurium showed that guanosine triphosphate binding induces a conformational rearrangement of helix 2.

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Sulfurtransferases transfer of sulfur atoms from thiols to acceptors like cyanide. They are categorized as thiosulfate sulfurtransferases (TSTs) and 3-mercaptopyruvate sulfurtransferases (MSTs). TSTs transfer sulfur from thiosulfate to cyanide, producing thiocyanate.

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Many polar organisms produce antifreeze proteins (AFPs) and ice-binding proteins (IBPs) to protect themselves from ice formation. As IBPs protect cells and organisms, the potential of IBPs as natural or biological cryoprotective agents (CPAs) for the cryopreservation of animal cells, such as oocytes and sperm, has been explored to increase the recovery rate after freezing-thawing. However, only a few IBPs have shown success in cryopreservation, possibly because of the presence of protein denaturants, such as dimethyl sulfoxide, alcohols, or ethylene glycol, in freezing buffer conditions, rendering the IBPs inactive.

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Esterase, a member of the serine hydrolase family, catalyzes the cleavage and formation of ester bonds with high regio- and stereospecificity, making them attractive biocatalysts for the synthesis of optically pure molecules. In this study, we performed an in-depth biochemical and structural characterization of a novel microbial acetylesterase, LgEstI, from the bacterial fish pathogen Lactococcus garvieae. The dimeric LgEstI displayed substrate preference for the short acyl chain of p-nitrophenyl esters and exhibited increased activity with F207A mutation.

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Cytochrome P450 (CYP) is a heme-containing enzyme that catalyzes hydroxylation reactions with various substrate molecules. Steroid hydroxylases are particularly useful for effectively introducing hydroxyl groups into a wide range of steroids in the pharmaceutical industry. This study reports a newly identified CYP steroid hydroxylase (CYP106A6) from the bacterium sp.

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Article Synopsis
  • S-Formylglutathione hydrolase (VaSFGH) is an enzyme that primarily breaks down S-formylglutathione but can also act on other thioester and ester compounds.
  • * Researchers discovered the VaSFGH gene in an Antarctic bacterium and characterized its protein, finding it works best on short-chain p-nitrophenyl esters.
  • * The study revealed the crystal structure of VaSFGH, showing limitations in its substrate-binding pocket that affect its ability to process larger substrates, which is valuable for future enzyme modifications for industrial applications.
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The rice pathogen uses amino acids as a principal carbon source and thus produces ammonia in amino acid-rich culture medium such as Luria-Bertani (LB) broth. To counteract ammonia-mediated environmental alkaline toxicity, the bacterium produces a public good, oxalate, in a quorum sensing (QS)-dependent manner. QS mutants of experience alkaline toxicity and may undergo cell death at the stationary phase when grown in LB medium.

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