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Jean-Emmanuel Hugonnet, Dominique Mengin-Lecreulx, Alejandro Monton, Tanneke den Blaauwen, Etienne Carbonnelle, Carole Veckerlé, Yves Brun, Michael van Nieuwenhze, Christiane Bouchier, Kuyek Tu, Louis B Rice, Michel Arthur
The target of β-lactam antibiotics is the D,D-transpeptidase activity of penicillin-binding proteins (PBPs) for synthesis of 4→3 cross-links in the peptidoglycan of bacterial cell walls. Unusual 3→3 cross-links formed by L,D-transpeptidases were first detected in Escherichia coli more than four decades ago, however no phenotype has previously been associated with their synthesis. Here we show that production of the L,D-transpeptidase YcbB in combination with elevated synthesis of the (p)ppGpp alarmone by RelA lead to full bypass of the D,D-transpeptidase activity of PBPs and to broad-spectrum β-lactam resistance...
October 21, 2016: ELife
Kimberly F Starr, Eric A Porsch, Patrick C Seed, Christian Heiss, Radnaa Naran, L Scott Forsberg, Uri Amit, Pablo Yagupsky, Parastoo Azadi, Joseph W St Geme
Kingella kingae is an encapsulated gram-negative organism that is a common cause of osteoarticular infections in young children. In earlier work, we identified a glycosyltransferase gene called csaA that is necessary for synthesis of the [3)-β-GalpNAc-(1→5)-β-Kdop-(2→] polysaccharide capsule (type a) in K. kingae strain 269-492. In the current study, we analyzed a large collection of invasive and carrier isolates from Israel and found that csaA was present in only 47% of the isolates. Further examination of this collection using primers based on the sequence that flanks csaA revealed three additional gene clusters (designated the csb, csc, and csd loci), all encoding predicted glycosyltransferases...
October 2016: PLoS Pathogens
Maria Manuela Rigano, Assunta Raiola, Teresa Docimo, Valentino Ruggieri, Roberta Calafiore, Paola Vitaglione, Rosalia Ferracane, Luigi Frusciante, Amalia Barone
Solanum lycopersicum represents an important dietary source of bioactive compounds including the antioxidants flavonoids and phenolic acids. We previously identified two genotypes (IL7-3 and IL12-4) carrying loci from the wild species Solanum pennellii, which increased antioxidants in the fruit. Successively, these lines were crossed and two genotypes carrying both introgressions at the homozygous condition (DHO88 and DHO88-SL) were selected. The amount of total antioxidant compounds was increased in DHOs compared to both ILs and the control genotype M82...
2016: Frontiers in Plant Science
Shilpi Yadav, Jonathan K Williamson, Maria A Aronova, Andrew A Prince, Irina D Pokrovskaya, Richard D Leapman, Brian Storrie
Platelets are small, anucleate cell fragments that are central to hemostasis, thrombosis, and inflammation. They are derived from megakaryocytes from which they inherit their organelles. As platelets can synthesize proteins and contain many of the enzymes of the secretory pathway, one might expect all mature human platelets to contain a stacked Golgi apparatus, the central organelle of the secretory pathway. By thin section electron microscopy, stacked membranes resembling the stacked Golgi compartment in megakaryocytes and other nucleated cells can be detected in both proplatelets and platelets...
October 18, 2016: Platelets
Min Pang, Xin-Yan Bai, Yan Li, Ji-Zhong Bai, Li-Rong Yuan, Shou-An Ren, Xiao-Yun Hu, Xin-Ri Zhang, Bao-Feng Yu, Rui Guo, Hai-Long Wang
Clara cell protein (CC16) is an anti-inflammatory protein, which is expressed in the airway epithelium. It is involved in the development of airway inflammatory diseases, including chronic obstructive pulmonary disease and asthma. However, the exact molecular mechanism underlying its anti‑inflammatory action remains to be fully elucidated. The aim of the present study was to define the protein profiles of the anti‑inflammatory effect of CC16 in lipopolysaccharide (LPS)‑treated rat tracheal epithelial (RTE) cells using shotgun proteomics...
October 12, 2016: Molecular Medicine Reports
Y Sun, L M Willis, H R Batchelder, M Nitz
Using a MALDI-MS based assay, the kinetic parameters for peptide glucosylation using the C. difficile toxin B glycosyltransferase domain were determined. The minimum consensus sequence for glucosylation was YXXTXFXXY and the optimal peptide found was YAPTVFDAY. Using this sequence, homogenous glucosylated proteins could be readily produced.
October 17, 2016: Chemical Communications: Chem Comm
Pan Li, Yan-Jie Li, Bo Wang, Hui-Min Yu, Qin Li, Bing-Kai Hou
Glycosyltransferase (GT) family-1, the biggest GT family in plants, typically participates in modification of small molecules and affects many aspects during plant development. In Arabidopsis thaliana, although some UDP glycosyltransferases (UGTs) of family-1 have been functionally characterized, functions of most UGTs remain unknown or fragmentary. Here, we report data for the arabidopsis UGT87A2, a stress-regulated glycosyltransferase. We found that UGT87A2 could be dramatically induced by salinity, osmotic stress, drought and ABA...
October 17, 2016: Physiologia Plantarum
Jinxin Li, Shujie Liu, Juan Wang, Jing Li, Dahui Liu, Jianli Li, Wenyuan Gao
In this work, we selected three fungi strains (Aspergillus niger, Aspergillus flavus and Aspergillus oryzae) as elicitors prepared from mycelium or fermentation broth to improve ginsenosides production in adventitious roots culture. The results showed that ginsenosides production (29.90±4.67mgg(-1)) was significantly enhanced upon elicitation with 200mgL(-1)A. niger elicitor prepared from mycelium, which was 3.52-fold of untreated group. HPLC-ESI-MS(n) analysis was performed, showing that ginsenoside Rb3 was present after treatment with the A...
October 13, 2016: Journal of Biotechnology
Virginia Lorenz, Yanina Ditamo, Romina B Cejas, Maria E Carrizo, Eric P Bennett, Henrik Clausen, Gustavo A Nores, Fernando J Irazoqui
Glycan biosynthesis occurs mainly in Golgi. Molecular organization and functional regulation of this process are not well understood. We evaluated the extrinsic effect of lectin domains (β-trefoil fold) of polypeptide GalNAc-transferases (ppGalNAc-Ts) on catalytic activity of glycosyltransferases during O-GalNAc glycan biosynthesis. The presence of lectin domain T3lec or T4lec during ppGalNAc-T2 and ppGalNAc-T3 catalytic reaction had a clear inhibitory effect on GalNAc-T activity. Interaction of T3lec or T4lec with ppGalNAc-T2 catalytic domain was not mediated by carbohydrate...
October 13, 2016: Journal of Biological Chemistry
Tingjing Zhang, Jianqiang Liang, Panxue Wang, Ying Xu, Yutang Wang, Xinyuan Wei, Mingtao Fan
Phloretin-2'-O-glycosyltransferase (P2'GT) catalyzes the last glycosylation step in the biosynthesis of phloridzin that contributes to the flavor, color and health benefits of apples and processed apple products. In this work, a novel P2'GT of Malus x domestica (MdP2'GT) with a specific activity of 46.82 μkat/Kg protein toward phloretin and uridine diphosphate glucose (UDPG) at an optimal temperature of 30 °C and pH 8.0 was purified from the engineered Pichia pastoris broth to homogeneity by anion exchange chromatography, His-Trap affinity chromatography and gel filtration...
October 12, 2016: Scientific Reports
Jianjun Pei, Ping Dong, Tao Wu, Linguo Zhao, Xianying Fang, Fuliang Cao, Feng Tang, Yongde Yue
Astragalin (kaempferol 3-O-glucoside) is used as a standard to assess the quality of Radix Astragali and has exhibited a number of biological properties. In this work, we screened several UDP-dependent glycosyltransferases (UGT) for their potential as efficient biocatalysts for astragalin synthesis. The highest astragalin production with 285 mg/L was detected in the recombinant strain expressing UGT from Arabidopis thaliana (AtUGT78D2). To further improve astragalin production, an efficient UDP-glucose synthesis pathway was reconstructed in the recombinant strain by introducing sucrose permease, sucrose phosphorylase and uridylyltransferase...
October 12, 2016: Journal of Agricultural and Food Chemistry
María Belem Arce-Vázquez, Edith Ponce-Alquicira, Ezequiel Delgado-Fornué, Ruth Pedroza-Islas, Gerardo Díaz-Godínez, J Soriano-Santos
Cyclodextrin glycosyltransferase (CGTase) is an enzyme that produces cyclodextrins (CDs) from starch and related carbohydrates, producing a mixture of α-, β-, and γ-CDs in different amounts. CGTase production, mainly by Bacillus sp., depends on fermentation conditions such as pH, temperature, concentration of nutrients, carbon and nitrogen sources, among others. Bacillus megaterium CGTase produces those three types of CDs, however, β-CD should prevail. Although, waxy corn starch (CS) is used industrially to obtain CGTase and CDs because of its high amylopectin content, alternative sources such as amaranth starch (AS) could be used to accomplish those purposes...
2016: Frontiers in Microbiology
Hafiz Mamoon Rehman, Muhammad Amjad Nawaz, Le Bao, Zahid Hussain Shah, Jae-Min Lee, Muhammad Qadir Ahmad, Gyuhwa Chung, Seung Hwan Yang
Family-1 UDP-glycosyltransferases (EC 2.4.1.x; UGTs) are enzymes that glycosylate aglycones into glycoside-associated compounds with improved transport and water solubility. This glycosylation mechanism is vital to plant functions, such as regulation of hormonal homeostasis, growth and development, xenobiotic detoxification, stress response, and biosynthesis of secondary metabolites. Here, we report a genome-wide analysis of soybean that identified 149 putative UGTs based on 44 conserved plant secondary product glycosyl-transferase (PSPG) motif amino acid sequences...
September 22, 2016: Journal of Plant Physiology
C Verde, D Giordano, C M Bellas, G di Prisco, A M Anesio
The large diversity of marine microorganisms harboured by oceans plays an important role in planet sustainability by driving globally important biogeochemical cycles; all primary and most secondary production in the oceans is performed by microorganisms. The largest part of the planet is covered by cold environments; consequently, cold-adapted microorganisms have crucial functional roles in globally important environmental processes and biogeochemical cycles cold-adapted extremophiles are a remarkable model to shed light on the molecular basis of survival at low temperature...
2016: Advances in Microbial Physiology
Sof'ya N Senchenkova, Xi Guo, Olesya I Naumenko, Alexander S Shashkov, Andrei V Perepelov, Bin Liu, Yuriy A Knirel
O-polysaccharides (OPSs) were obtained by mild acid degradation of the lipopolysaccharides of Escherichia coli O182-O187, and their structures were established by sugar analysis, Smith degradation, and (1)H and (13)C NMR spectroscopy. In addition to the monosaccharides that occur often in E. coli OPSs (d-Glc, d-Gal, d-Man, d-GlcNAc, d-GalNAc, d-GlcA, l-Fuc, d-Rib), a number of less common components were identified as the OPS constituents, including 2-acetamido-2-deoxy-l-quinovose and 4-deoxy-4-[(S)-3-hydroxybutanoyl-l-alanyl]-d-quinovose (O186), 3-acetamido-3-deoxy-d-fucose (O187), 3-deoxy-3-[(R)-3-hydroxybutanoyl]-d-fucose (O184), and 2,3-diacetamido-2,3-dideoxy-l-rhamnose (O182)...
September 23, 2016: Carbohydrate Research
Esmeralda Valiente, Laura Bouché, Paul Hitchen, Alexandra Faulds-Pain, Mario Songane, Lisa F Dawson, Elizabeth Donahue, Richard A Stabler, Maria Panico, Howard R Morris, Mona Bajaj-Elliott, Susan M Logan, Anne Dell, Brendan W Wren
Clostridium difficile is the principal cause of nosocomial infectious diarrhoea worldwide. The pathogen modifies its flagellin with either a type A or type B O-linked glycosylation system, which has a contributory role in pathogenesis. We study the functional role of glycosyltransferases modifying type B flagellin in the 023 and 027 hypervirulent C. difficile lineages by mutagenesis of five putative glycosyltransferases and biosynthetic genes. We reveal their roles in the biosynthesis of the flagellin glycan chain and demonstrate that flagellar post-translational modification affects motility and adhesion-related bacterial properties of these strains...
October 4, 2016: Journal of Biological Chemistry
Yang-Hsin Hsu, Takayoshi Tagami, Kana Matsunaga, Masayuki Okuyama, Takashi Suzuki, Naonobu Noda, Masahiko Suzuki, Hanako Shimura
Because structural modifications of flavonoids are closely related to their properties such as stability, solubility, flavor and coloration, characterizing the enzymes that catalyze the modification reactions can be useful for engineering agriculturally beneficial traits of flavonoids. In this work, we examined the enzymes involved in the modification pathway of highly glycosylated and acylated anthocyanins that accumulate in Lobelia erinus. Cultivar Aqua Blue (AB) of L. erinus is blue-flowered and accumulates delphinidin 3-O-p-coumaroylrutinoside-5-O-malonylglucoside-3'5'-O-dihydroxycinnamoylglucoside (lobelinins) in its petals...
October 3, 2016: Plant Journal: for Cell and Molecular Biology
Laura Astola, Hans Stigter, Maria Victoria Gomez Roldan, Fred van Eeuwijk, Robert D Hall, Marian Groenenboom, Jaap J Molenaar
We study the glycosylation processes that convert initially toxic substrates to nutritionally valuable metabolites in the flavonoid biosynthesis pathway of tomato (Solanum lycopersicum) seedlings. To estimate the reaction rates we use ordinary differential equations (ODEs) to model the enzyme kinetics. A popular choice is to use a system of linear ODEs with constant kinetic rates or to use Michaelis-Menten kinetics. In reality, the catalytic rates, which are affected among other factors by kinetic constants and enzyme concentrations, are changing in time and with the approaches just mentioned, this phenomenon cannot be described...
2016: PeerJ
Tokiaki Yamaguchi, Yoshio Yamauchi, Keiko Furukawa, Yuhsuke Ohmi, Yuki Ohkawa, Qing Zhang, Tetsuya Okajima, Koichi Furukawa
Alzheimer's disease (AD) is the most prevalent form of dementia characterized by the extracellular accumulation of amyloid β (Aβ) peptides, which are produced by proteolytic cleavages of amyloid precursor protein (APP). Gangliosides are involved in AD pathophysiology including Aβ deposition and APP processing, yet the detailed mechanisms are not fully understood. Here we examined how changes in the carbohydrate moiety of gangliosides alter APP processing in human melanoma cells, neuroectoderm-derived cells...
September 30, 2016: Scientific Reports
Wan-Ling Ho, Wen-Ming Hsu, Min-Chuan Huang, Kenji Kadomatsu, Akira Nakagawara
Glycosylation is the most complex post-translational modification of proteins. Altered glycans on the tumor- and host-cell surface and in the tumor microenvironment have been identified to mediate critical events in cancer pathogenesis and progression. Tumor-associated glycan changes comprise increased branching of N-glycans, higher density of O-glycans, generation of truncated versions of normal counterparts, and generation of unusual forms of terminal structures arising from sialylation and fucosylation. The functional role of tumor-associated glycans (Tn, sTn, T, and sLe(a/x)) is dependent on the interaction with lectins...
September 29, 2016: Journal of Hematology & Oncology
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