A5117283255The University of Texas at Austin
2019-2025
National Taiwan Normal University
1989
A small but growing set of radical SAM (S-adenosyl-l-methionine) enzymes catalyze the mediated dehydration or dehydrogenation 1,2-diol substrates. In some cases, these activities can be interchanged via minor structural perturbations to reacting components raising questions regarding relative importance hyperconjugation, proton circulation and leaving group stability in determining reaction outcome. The present work describes trapping electron paramagnetic resonance (EPR) characterization an...
Blasticidin S is a peptidyl nucleoside that blocks protein synthesis in prokaryotes and eukaryotes. It widely used molecular biology as selection agent. Despite its utility, the biosynthetic origin of 2′,3′-unsaturated-4′-aminoacyl-4′-deoxyhexopyranose core only partially understood. Previously, radical S-adenosylmethionine enzyme BlsE was shown to catalyze dehydration cytosylglucuronic acid. Herein, this product be accepted by pyridoxal phosphate-dependent BlsH catalyzing an α,β-dehydration...
Stereoselectivity of the Pictet–Spengler reaction catalyzed by KslB resolved crystal structure enzyme-product complex.
Peptidyl nucleoside antibiotics (PNAs) are a diverse class of natural products with promising biomedical activities. These compounds have tripartite structures composed core saccharide, nucleobase, and one or more amino acids. In particular, amipurimycin the miharamycins novel 2-aminopurinyl PNAs complex nine-carbon saccharides include unusual acids (−)-cispentacin N5-hydroxyarginine, respectively. Despite their interesting properties, these heretofore eluded biochemical scrutiny. Herein is...
OxsB is a B12-dependent radical SAM enzyme that catalyzes the oxidative ring contraction of 2′-deoxyadenosine 5′-phosphate to dehydrogenated, oxetane containing precursor oxetanocin A phosphate. AlsB homologue participates in similar reaction during biosynthesis albucidin. Herein, and are shown also catalyze mediated, stereoselective C2′-methylation monophosphate. This proceeds with inversion configuration such resulting product possesses C2′ hydrogen atom available for abstraction. However,...
The biosynthesis of blasticidin S has drawn attention due to the participation radical
Oxazinomycin is a C-nucleoside natural product with antibacterial and antitumor activities. In addition to the characteristic C-glycosidic linkage shared other C-nucleosides, oxazinomycin also features structurally unusual 1,3-oxazine moiety, biosynthesis of which had previously been unknown. Herein, complete in vitro reconstitution biosynthetic pathway described. Construction bond between ribose 5-phosphate an oxygen-labile pyridine heterocycle catalyzed by C-glycosidase OzmB involves...
Oxetanocin-A is an antitumor, antiviral, and antibacterial nucleoside. It biosynthesized via the oxidative ring contraction of a purine nucleoside co-opted from primary metabolism. This reaction catalyzed by B12-dependent radical S-adenosyl-l-methionine (SAM) enzyme, OxsB, phosphohydrolase, OxsA. Previous experiments showed that product OxsB/OxsA-catalyzed oxetane aldehyde produced alongside uncharacterized byproduct. Experiments reported herein reveal OxsB/OxsA complex formation crucial for...
Valanimycin is an azoxy-containing natural product isolated from the fermentation broth of Streptomyces viridifaciens MG456-hF10. While biosynthesis valanimycin has been partially characterized, how azoxy group constructed remains obscure. Herein, membrane protein VlmO and putative hydrazine synthetase ForJ formycin biosynthetic pathway are demonstrated to catalyze N-N bond formation converting O-(l-seryl)-isobutyl hydroxylamine into N-(isobutylamino)-l-serine. Subsequent installation shown...
Oxetanocin A and albucidin are two oxetane natural products. While the biosynthesis of oxetanocin has been described, less is known about albucidin. In this work, biosynthetic gene cluster identified in Streptomyces. Heterologous expression a nonproducing strain demonstrates that genes alsA alsB necessary sufficient for confirming previous study (Myronovskyi et al. Microorganisms 2020, 8, 237). two-step construction 4'-phosphate from 2'-deoxyadenosine monophosphate (2'-dAMP) shown to be...
Abstract Oxetanocin A and albucidin are two oxetane natural products. While the biosynthesis of oxetanocin has been described, less is known about albucidin. In this work, biosynthetic gene cluster identified in Streptomyces . Heterologous expression a nonproducing strain demonstrates that genes alsA alsB necessary sufficient for confirming previous study (Myronovskyi et al. Microorganisms 2020 , 8 237). two‐step construction 4′‐phosphate from 2′‐deoxyadenosine monophosphate (2′‐dAMP) shown...
Abstract An investigation of benzylic oxidations with manganese dioxide supported on neutral alumina has been carried out. Isolation intermediated products, which is possible in some cases, gives strong support for the reaction mechanism proposed. With 2,6‐di‐tert‐butyl‐4‐methylphenol, 4,4′‐dihydroxy‐3,5,3′,5′‐tetra‐tert‐butyldiphenylmethane,2,6‐di‐tert‐butylphenol and 4‐methyl‐phenol, selective formation essentially a single product excellent yield was obtained.
Abstract Valanimycin is an azoxy‐containing natural product isolated from the fermentation broth of Streptomyces viridifaciens MG456‐hF10. While biosynthesis valanimycin has been partially characterized, how azoxy group constructed remains obscure. Herein, membrane protein VlmO and putative hydrazine synthetase ForJ formycin biosynthetic pathway are demonstrated to catalyze N−N bond formation converting O ‐( l ‐seryl)‐isobutyl hydroxylamine into N ‐(isobutylamino)‐ ‐serine. Subsequent...
Mowat-Wilson症候群是一種極為罕見的疾病，為ZEB2基因突變造成。此疾病會造成全身性的影響：包含明顯的臉部特徵、心血管疾病、先天性巨結腸症、智力遲緩以及癲癇。在此病例報告中會介紹此種症候群，以及描述一位9歲女性患者在全身麻醉下做牙科治療的過程。