Triterpenoid saponins are widely used in medicine, health cares, cosmetics, food additives and agriculture because of their unique chemical properties and rich pharmacological activities. UDP-dependent glycosyltransferases (UGTs) are the key enzymes involved in triterpenoid saponin biosynthesis, and play important roles in the diversity of triterpenoid saponin structures and pharmacological activities. This review summarized the UGTs involved in plant triterpenoid saponin biosynthesis based on the sources of UGTs and the types of receptors. Moreover, the application of UGTs in heterologous biosynthesis of triterpenoid saponins based on synthetic biology was also discussed.
Glycosyltransferases/genetics* ; Plants ; Saponins/chemistry* ; Triterpenes

Water solubility, stability, and bioavailability, can be substantially improved after glycosylation. Glycosylation of bioactive compounds catalyzed by glycoside hydrolases (GHs) and glycosyltransferases (GTs) has become a research hotspot. Thanks to their rich sources and use of cheap glycosyl donors, GHs are advantageous in terms of scaled catalysis compared to GTs. Among GHs, sucrose phosphorylase has attracted extensive attentions in chemical engineering due to its prominent glycosylation activity as well as its acceptor promiscuity. This paper reviews the structure, catalytic characteristics, and directional redesign of sucrose phosphorylase. Meanwhile, glycosylation of diverse chemicals with sucrose phosphorylase and its coupling applications with other biocatalysts are summarized. Future research directions were also discussed based on the current research progress combined with our working experience.
Glucosyltransferases/metabolism* ; Glycoside Hydrolases/metabolism* ; Glycosylation ; Glycosyltransferases/genetics*

OBJECTIVE: To explore the genetic basis of three children with unexplained mental retardation/developmental delay. METHODS: Peripheral venous blood samples were collected for routine G-banding karyotyping analysis and chromosomal microarray analysis (CMA). Whole exome sequencing (WES) was also carried out for patient 3. RESULTS: The karyotypes of the 3 children were normal. The result of CMA analysis of patient 1 was arr[GRCh37]: 2q22/3(145 128 071-145 159 029)×1, with a 31 kb deletion, which was predicted to be a pathogenic copy number variation. The deletion has involved exons 8 to 10 of the ZEB2 gene. Patient 2 was arr[hg19]:2q22.3 (145 071 457-146 881 759)×1, with a 1.81 Mb deletion involving the ZEB2 and GTDC1 genes. Patient 3 was arr[GRCh37]: 9p23p23(11 698 261-12 106 261)×1, with a 408 kb deletion containing no disease-associated gene. WES has identified a c.2102C>A (p.Ser701*) variant in exon 8 of the ZEB2 gene, which was included in ClinVar database and rated as pathogenic, and verified by Sanger sequencing as a de novo variant. CONCLUSION For the substantial clinical and genetic heterogeneity of Mowat-Wilson-syndrome, CMA and WES are helpful to identify the etiology of children with developmental delay/mental retardation of unknown causes, particularly those with peculiar facial features and multiple congenital malformations.
Child ; DNA Copy Number Variations ; Facies ; Glycosyltransferases/genetics* ; Hirschsprung Disease ; Humans ; Intellectual Disability/genetics* ; Microcephaly/genetics*

OBJECTIVE: To explore the molecular basis for an individual with Bw subtype. METHODS: Routine serological reactions were used to determine the surface antigens of erythrocytes and antibodies in serum. PCR-sequence-based typing (PCR-SBT) was used to analyze the coding regions of the ABO gene and erythroid-specific regulatory element in its intron 1. Amplicons for exons 5 to 7 containing the variant site were subjected to TA cloning for the isolation of the haploid and verification of the sequence. The 3D structure of mutant protein was predicted with Pymol software. Changes of amino acid residues and structural stability were also analyzed. RESULTS: Serological assay showed that the individual had weakened B antigen and anti-B antibody in his serum. His genotype was determined as ABO*B.01/ABO*O.01.01. Sequencing of the entire coding region of the ABO gene identified an additional heterozygous c.734C/T variant. No variant was found in the erythroid-specific regulatory element of intron 1. Haploid cloning and isolation has obtained an ABO*O.01.01 allele and a ABO*B.01 allele containing a c.734T variant, which has led to substitution of Thr by Ile at position 245 in the functional center of glycosyltransferase. Based on the 3D structure of the protein, the residues binding with the mutation were unchanged, but the bonding distance between the hydrogens was changed with the amino acid substitution. Meanwhile, the connections with water molecules were increased. CONCLUSION The c.734C>T variant of the GTB gene can lead to an amino acid substitution in the functional center of the enzyme, which in turn may affect the stability of glycosyltransferase B protein and reduceits enzymatic activity.
ABO Blood-Group System/genetics* ; Alleles ; Exons/genetics* ; Genotype ; Glycosyltransferases/genetics* ; Humans ; Male ; Phenotype

OBJECTIVETo explore the molecular basis of an individual featuring an ABx variant of ABO blood group system.

METHODSSerological assays were used to characterize the erythrocyte phenotypes and salivary ABH secretors. All of the seven exons and flanking introns of ABO glycosyltransferase gene were amplified with polymerase chain reaction (PCR). And the products were sequenced bidirectionally following enzyme digestion. Exons 6 and 7 were also subcloned and analyzed for haplotypes of the ABO gene.

RESULTSErythrocytes of the proband have expressed a strong A antigen and a weak B antigen, which was identified as a rare ABx variant in addition with other serological features. Nine heterozygous sites in exon 6 (297A/G) and exon 7 (467C/T, 526C/G, 657C/T, 703G/A, 796C/A, 803G/C, 808T/A, 930G/A) of the coding region of the ABO gene were identified. Based on haplotype analysis, one allele was determined as common A102, whilst another was consistent with B101 except for an 808T>A mutation which has resulted in replacement of phenylalanine with isoleucine at position 270 of glycosyltransferase B.

CONCLUSIONThe 808T>A mutation of the glycosyltransferase B gene may decrease the enzymatic activity and result in the Bx variant.

ABO Blood-Group System ; genetics ; Adult ; Exons ; Female ; Glycosyltransferases ; genetics ; Haplotypes ; Humans ; Mutation

Caffeic acid and its oligomers are the main water-soluble active constituents of the traditional Chinese medicine(TCM) Arnebiae Radix. These compounds possess multiple biological activities such as antimicrobial, antioxidant, cardiovascular protective, liver protective, anti-liver fibrosis, antiviral and anticancer activities. The phenylpropanoid pathway in plants is responsible for the biosynthesis of caffeic acid and its oligomers. Glycosylation can change phenylpropanoid solubility, stability and toxic potential, as well as influencing compartmentalization and biological activity. In view of the important role played by de-glycosylation in the regulation of phenylpropanoid homeostasis, the biosynthesis of caffeic acid and its oligomers are supposed to be under the control of relative UDP-glycosyltransferases(UGTs). Through the data mining of Arnebia euchroma transcriptome, we cloned 15 full-length putative UGT genes. After recombinant expression using the prokaryotic system, the crude enzyme solution of the putative UGTs was examined for the glycosylation activities towards caffeic acid and rosmarinic acid in vitro. AeUGT_01, AeUGT_02, AeUGT_03, AeUGT_04 and AeUGT_10 were able to glycosylate caffeic acid and/or rosmarinic acid resulting in different mono-and/or di-glycosylated products in the UPLC-MS analyses. The characterized UGTs were distantly related to each other and divided into different clades of the phylogenetic tree. Based on the observation that each characterized UGT exhibited substrate or catalytic similarity with the members in their own clade, we supposed the glycosylation abilities towards caffeic acid and/or rosmarinic acid were evolved independently in different clades. The identification of caffeic acid and rosmarinic acid UGTs from A. euchroma could lead to deeper understanding of the caffeic acid oligomers biosynthesis and its regulation. Furthermore, these UGTs might be used for regiospecific glycosylation of caffeic acid and rosmarinic acid to produce bioactive compounds for potential therapeutic applications.
Boraginaceae/genetics* ; Caffeic Acids ; Chromatography, Liquid ; Cinnamates ; Cloning, Molecular ; Depsides ; Glycosyltransferases/genetics* ; Phylogeny ; Tandem Mass Spectrometry

The lignan glycosyltransferase UGT236(belonging to the UGT71 B family) from Isatis indigotica can catalyze the production of phloridzin from phloretin in vitro. UGT236 shares high identity with P2'GT from apple. In this study, the recombinant plasmid pET28 a-MBP-UGT236 was transferred into Escherichia coli Rosetta(DE3) cells and induced by isopropyl-β-D-thiogalactoside(IPTG). The purified UGT236 protein was used for enzymatic characterization with phloretin as substrate. The results showed that UGT236 had the optimal reaction temperature of 40 ℃ and the optimal pH 8(Na_2HPO_4-NaH_2PO_4 system). The UGT236 activity was inhibited by Ni~(2+) and Al~(3+), enhanced by Fe~(2+), Co~(2+), and Mn~(2+), and did not affected by Mg~(2+), Ca~(2+), Li~+, Na~+, or K~+. The K_m, K_(cat), and K_(cat)/K_m of phloretin were 61.03 μmol·L~(-1), 0.01 s~(-1), and 157.11 mol~(-1)·s~(-1)·L, and those of UDPG were 183.6 μmol·L~(-1), 0.01 s~(-1), and 51.91 mol~(-1)·s~(-1)·L, respectively. The possible active sites were predicted by homologous modeling and molecular docking. By mutagenisis and catalytic activity detection, three key active sites, Glu391, His15, and Thr141, were identified, while Phe146 was related to product diversity. In summary, we found that the lignan glycosyltransferase UGT236 from I.indigotica could catalyze the reaction of phloretin into phloridzin. Several key amino acid residues were identified by structure prediction, molecular docking, and site-mutagenesis, which provided a basis for studying the specificity and diversity of phloretin glycoside products. This study can provide a reference for artificially producing glycosyltransferase elements with high efficiency and specific catalysis.
Glucosyltransferases/genetics* ; Glycosyltransferases/metabolism* ; Isatis ; Lignans/metabolism* ; Molecular Docking Simulation ; Phloretin/metabolism* ; Phlorhizin/metabolism*

Carthami Flos, as a traditional blood-activating and stasis-resolving drug, possesses anti-tumor, anti-inflammatory, and immunomodulatory pharmacological activities. Flavonoid glycosides are the main bioactive components in Carthamus tinctorius. Glycosyltransferase deserves to be studied in depth as a downstream modification enzyme in the biosynthesis of active glycoside compounds. This study reported a flavonoid glycosyltransferase CtUGT49 from C. tinctorius based on the transcriptome data, followed by bioinformatic analysis and the investigation of enzymatic properties. The open reading frame(ORF) of the gene was 1 416 bp, encoding 471 amino acid residues with the molecular weight of about 52 kDa. Phylogenetic analysis showed that CtUGT49 belonged to the UGT73 family. According to in vitro enzymatic results, CtUGT49 could catalyze naringenin chalcone to the prunin and choerospondin, and catalyze phloretin to phlorizin and trilobatin, exhibiting good substrate versatility. After the recombinant protein CtUGT49 was obtained by hetero-logous expression and purification, the enzymatic properties of CtUGT49 catalyzing the formation of prunin from naringenin chalcone were investigated. The results showed that the optimal pH value for CtUGT49 catalysis was 7.0, the optimal temperature was 37 ℃, and the highest substrate conversion rate was achieved after 8 h of reaction. The results of enzymatic kinetic parameters showed that the K_m value was 209.90 μmol·L~(-1) and k_(cat) was 48.36 s~(-1) calculated with the method of Michaelis-Menten plot. The discovery of the novel glycosyltransferase CtUGT49 is important for enriching the library of glycosylation tool enzymes and provides a basis for analyzing the glycosylation process of flavonoid glycosides in C. tinctorius.
Carthamus tinctorius/chemistry* ; Phylogeny ; Flavonoids/analysis* ; Glycosides/analysis* ; Glycosyltransferases/genetics* ; Anti-Inflammatory Agents ; Chalcones

Uridine diphosphate glycosyltransferase(UGT) is a highly conserved protein in plants, which usually functions in secondary metabolic pathways. This study used the Hidden Markov Model(HMM) to screen out members of UGT gene family in the whole genome of Dendrobium officinale, and 44 UGT genes were identified. Bioinformatics was used to analyze the structure, phylogeny, and promoter region components of D. officinale genes. The results showed that UGT gene family could be divided into four subfamilies, and UGT gene structure was relatively conserved in each subfamily, with nine conserved domains. The upstream promoter region of UGT gene contained a variety of cis-acting elements related to plant hormones and environmental factors, indicating that UGT gene expression may be induced by plant hormones and external environmental factors. UGT gene expression in different tissues of D. officinale was compared, and UGT gene expression was found in all parts of D. officinale. It was speculated that UGT gene played an important role in many tissues of D. officinale. Through transcriptome analysis of D. officinale mycorrhizal symbiosis environment, low temperature stress, and phosphorus deficiency stress, this study found that only one gene was up-regulated in all three conditions. The results of this study can help understand the functions of UGT gene family in Orchidaceae plants and provide a basis for further study on the molecular regulation mechanism of polysaccharide metabolism pathway in D. officinale.
Dendrobium/genetics* ; Plant Growth Regulators ; Glycosyltransferases/metabolism* ; Gene Expression Profiling ; Mycorrhizae ; Phylogeny ; Plant Proteins/metabolism*

In this study, the authors cloned a glycosyltransferase gene PpUGT2 from Paris polyphylla var. yunnanensis with the ORF length of 1 773 bp and encoding 590 amino acids. The phylogenetic tree revealed that PpUGT2 belonged to the UGT80A subfamily and was named as UGT80A49 by the UDP-glycosyltransferase(UGT) Nomenclature Committee. The expression vector pET28a-PpUGT2 was constructed, and enzyme catalytic reaction in vitro was conducted via inducing protein expression and extraction. With UDP-glucose as sugar donor and diosgenin and pennogenin as substrates, the protein was found with the ability to catalyze the C-3 hydroxyl β-glycosylation of diosgenin and pennogenin. To further explore its catalytic characteristic, 15 substrates including steroids and triterpenes were selected and PpUGT2 showed its activity towards the C-17 position of sterol testosterone with UDP-glucose as sugar donor. Homology modelling and molecule docking of PpUGT2 with substrates predicted the key residues interacting with ligands. The re-levant residues of PpUGT2-ligand binding model were scanned to calculate the corresponding mutants, and the optimized mutants were obtained according to the changes in binding affinity of the ligand with protein and the surrounding residues within 5.0 Å of ligands, which had reference value for design of the mutants. This study laid a foundation for further exploring the biosynthetic pathway of polyphyllin as well as the structure of sterol glycosyltransferases.
Ligands ; Glycosyltransferases/genetics* ; Sterols ; Phylogeny ; Ascomycota ; Liliaceae/chemistry* ; Melanthiaceae ; Diosgenin ; Sugars ; Glucose ; Uridine Diphosphate