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S-Adenosyl methionine

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https://www.readbyqxmd.com/read/28301141/reconstitution-and-substrate-specificity-of-the-radical-sam-thiazole-c-methyltransferase-in-thiomuracin-biosynthesis
#1
Nilkamal Mahanta, Zhengan Zhang, Graham A Hudson, Wilfred A van der Donk, Douglas A Mitchell
Thiomuracin is a thiopeptide antibiotic with potent activity towards Gram-positive drug-resistant bacteria. Thiomuracin is biosynthesized from a precursor peptide, TbtA, by a complex array of posttranslational modifications. One of several intriguing transformations is the C-methylation of thiazole, occurring at an unactivated sp2 carbon. Herein, we report the in vitro reconstitution of TbtI, the responsible radical S-adenosyl-methionine (rSAM) C-methyltransferase, which catalyzes the formation of 5-methylthiazole at a single site...
March 16, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28293840/assay-methods-for-acs-activity-and-acs-phosphorylation-by-map-kinases-in-vitro-and-in-vivo
#2
Xiaomin Han, Guojing Li, Shuqun Zhang
Ethylene, a gaseous phytohormone, has profound effects on plant growth, development, and adaptation to the environment. Ethylene-regulated processes begin with the induction of ethylene biosynthesis. There are two key steps in ethylene biosynthesis. The first is the biosynthesis of 1-aminocyclopropane-1-carboxylic acid (ACC) from S-Adenosyl-Methionine (SAM), a common precursor in many metabolic pathways, which is catalyzed by ACC synthase (ACS). The second is the oxidative cleavage of ACC to form ethylene under the action of ACC oxidase (ACO)...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28276759/cloning-and-functional-analysis-of-two-sterol-c24-methyltransferase-1-smt1-genes-from-paris-polyphylla
#3
Hong-Yu Guan, Ping Su, Yu-Jun Zhao, Xia-Nan Zhang, Zhu-Bo Dai, Juan Guo, Yu-Ru Tong, Yu-Jia Liu, Tian-Yuan Hu, Yan Yin, Lin-Hui Gao, Wei Gao, Lu-Qi Huang
The biosynthetic pathways of phytosterols and steroidal saponins are located in two adjacent branches which share cycloartenol as substrate. The rate-limiting enzyme S-adenosyl-L-methionine-sterol-C24-methyltransferase 1 (SMT1) facilitates the metabolic flux toward phytosterols. It catalyzes the methylation of the cycloartenol in the side chain of the C24-alkyl group, to generate 24(28)-methylene cycloartenol. In this study, we obtained two full-length sequences of SMT1 genes from Pari polyphylla, designated PpSMT1-1 and PpSMT1-2...
February 23, 2017: Journal of Asian Natural Products Research
https://www.readbyqxmd.com/read/28259085/recent-advances-in-methyltransferase-biocatalysis
#4
REVIEW
Matthew R Bennett, Sarah A Shepherd, Victoria A Cronin, Jason Micklefield
S-adenosyl-L-methionine-dependent methyltransferses are ubiquitous in nature, methylating a vast range of small molecule metabolites, as well as biopolymers. This review covers the recent advances in the development of methyltransferase enzymes for synthetic applications, focusing on the methyltransferase catalyzed transformations with S-adenosyl methionine analogs, as well as non-native substrates. We discuss how metabolic engineering approaches have been used to enhance S-adenosyl methionine production in vivo...
March 2, 2017: Current Opinion in Chemical Biology
https://www.readbyqxmd.com/read/28255539/the-activity-of-a-yeast-family-16-methyltransferase-efm2-is-affected-by-a-conserved-tryptophan-and-its-n-terminal-region
#5
Joshua J Hamey, Gene Hart-Smith, Melissa A Erce, Marc R Wilkins
The Family 16 methyltransferases are a group of eukaryotic nonhistone protein methyltransferases. Sixteen of these have recently been described in yeast and human, but little is known about their sequence and structural features. Here we investigate one of these methyltransferases, Saccharomyces cerevisiae elongation factor methyltransferase 2 (Efm2), by site-directed mutagenesis and truncation. We show that an active site-associated tryptophan, invariant in Family 16 methyltransferases and at position 222 in Efm2, is important for methyltransferase activity...
December 2016: FEBS Open Bio
https://www.readbyqxmd.com/read/28237804/s-adenosyl-methionine-sam-attenuates-the-development-of-tolerance-to-analgesic-activity-of-morphine-in-rats
#6
Jatinder Katyal, Hemant Kumar, Dinesh Joshi, Yogendra Kumar Gupta
BACKGROUND: Development of tolerance to analgesic effect, on chronic administration of morphine, limits its clinical usefulness in pain management. S-adenosyl methionine (SAM) used for arthritis and approved as a supplement in many countries including United States was evaluated for reducing morphine tolerance. METHODS: Male 'Wistar' rats were used. The analgesic activity was determined using tail flick analgesiometer (Columbus Instruments, USA). Rats given morphine (7mg/kg), intraperitoneally (i...
February 22, 2017: Neuroscience Letters
https://www.readbyqxmd.com/read/28237325/the-effect-of-lysophosphatidic-acid-together-with-interferon-tau-on-the-global-transcriptomic-profile-in-bovine-endometrial-cells
#7
Dorota Boruszewska, Ilona Kowalczyk-Zieba, Emilia Sinderewicz, Katarzyna Grycmacher, Joanna Staszkiewicz, Izabela Woclawek-Potocka
In cows, lysophosphatidic acid (LPA), which acts in an auto/paracrine manner, serves as a luteotropic factor during early pregnancy by stimulating progesterone and prostaglandin E2 secretion, thus protecting the bovine corpus luteum and early embryo development. Our hypothesis was that LPA exerted some local effects on the bovine endometrium prior to early embryo-maternal interactions and that interferon tau (IFNτ), the pregnancy recognition signal, modulated this action. In the present study, we applied an in vitro model involving whole-transcriptomic profiling to examine the effects of LPA on gene expression in bovine endometrial cells...
April 1, 2017: Theriogenology
https://www.readbyqxmd.com/read/28237031/single-nucleotide-polymorphisms-may-explain-the-contrasting-phenotypes-of-two-variants-of-a-multidrug-resistant-mycobacterium-tuberculosis-strain
#8
María Mercedes Bigi, Beatriz Lopez, Federico Carlos Blanco, María Del Carmen Sasiain, Silvia De la Barrera, Marcelo A Marti, Ezequiel Jorge Sosa, Darío Augusto Fernández Do Porto, Viviana Ritacco, Fabiana Bigi, Marcelo Abel Soria
Globally, about 4.5% of new tuberculosis (TB) cases are multi-drug-resistant (MDR), i.e. resistant to the two most powerful first-line anti-TB drugs. Indeed, 480,000 people developed MDR-TB in 2015 and 190,000 people died because of MDR-TB. The MDR Mycobacterium tuberculosis M family, which belongs to the Haarlem lineage, is highly prosperous in Argentina and capable of building up further drug resistance without impairing its ability to spread. In this study, we sequenced the whole genomes of a highly prosperous M-family strain (Mp) and its contemporary variant, strain 410, which produced only one recorded tuberculosis case in the last two decades...
March 2017: Tuberculosis
https://www.readbyqxmd.com/read/28229434/preclinical-pharmacokinetics-and-pharmacodynamics-of-pinometostat-epz-5676-a-first-in-class-small-molecule-s-adenosyl-methionine-competitive-inhibitor-of-dot1l
#9
Nigel J Waters
Acute leukemias bearing mixed lineage leukemia (MLL) rearrangements are aggressive diseases characterized by a poor overall prognosis despite multi-agent chemotherapy. Aberrant fusion proteins involving the MLL histone methyltransferase (HMT) lead to recruitment of DOT1L, to a multi-protein complex resulting in aberrant methylation of histone H3 lysine 79 at MLL target genes, and ultimately enhanced expression of critical genes for hematopoietic differentiation, including HOXA9 and MEIS1, and as such defines the established mechanism for leukemogenesis in MLL-rearrangement (MLL-r) leukemias...
February 22, 2017: European Journal of Drug Metabolism and Pharmacokinetics
https://www.readbyqxmd.com/read/28225105/elucidating-the-biosynthetic-pathways-of-volatile-organic-compounds-in-mycobacterium-tuberculosis-through-a-computational-approach
#10
Purva Bhatter, Karthik Raman, Vani Janakiraman
Microbial volatile organic compounds (VOCs) have gained prominence in the recent past for their potential use as disease markers. The discovery of microbial VOCs has benefited 'difficult to detect' diseases such as tuberculosis (TB). Few of the identified VOCs of Mycobacterium tuberculosis (Mtb) are currently being explored for their diagnostic potential. However, very little is known about the biosynthesis of these small lipophilic molecules. Here, we propose putative biosynthetic pathways in Mycobacterium tuberculosis for three VOCs, namely methyl nicotinate, methyl phenylacetate and methyl p-anisate, using computational approaches...
February 22, 2017: Molecular BioSystems
https://www.readbyqxmd.com/read/28224386/%C3%AE-bisabolol-inhibits-aspergillus-fumigatus-af239-growth-via-affecting-microsomal-%C3%A2-24-sterol-methyltransferase-as-a-crucial-enzyme-in-ergosterol-biosynthesis-pathway
#11
Zahra Jahanshiri, Masoomeh Shams-Ghahfarokhi, Farnoush Asghari-Paskiabi, Reza Saghiri, Mehdi Razzaghi-Abyaneh
Finding new compounds with antifungal properties is an important task due to the side effects of common antifungal drugs and emerging antifungal resistance in fungal strains. ∆(24)-sterol methyltransferase (24-SMT) is a crucial enzyme that plays important roles in fungal ergosterol biosynthesis pathway and is not found in humans. In the present study, the effects of α-bisabolol on Aspergillus fumigatus Af239 growth and ergosterol synthesis on the base of 24-SMT enzyme activity were studied; in addition, the expression of erg6, the gene encoded 24-SMT, was considered...
March 2017: World Journal of Microbiology & Biotechnology
https://www.readbyqxmd.com/read/28221344/chemoproteomic-profiling-and-discovery-of-protein-electrophiles-in-human-cells
#12
Megan L Matthews, Lin He, Benjamin D Horning, Erika J Olson, Bruno E Correia, John R Yates, Philip E Dawson, Benjamin F Cravatt
Activity-based protein profiling (ABPP) serves as a chemical proteomic platform to discover and characterize functional amino acids in proteins on the basis of their enhanced reactivity towards small-molecule probes. This approach, to date, has mainly targeted nucleophilic functional groups, such as the side chains of serine and cysteine, using electrophilic probes. Here we show that 'reverse-polarity' (RP)-ABPP using clickable, nucleophilic hydrazine probes can capture and identify protein-bound electrophiles in cells...
March 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28216563/the-genomic-impact-of-dna-cpg-methylation-on-gene-expression-relationships-in-prostate-cancer
#13
REVIEW
Mark D Long, Dominic J Smiraglia, Moray J Campbell
The process of DNA CpG methylation has been extensively investigated for over 50 years and revealed associations between changing methylation status of CpG islands and gene expression. As a result, DNA CpG methylation is implicated in the control of gene expression in developmental and homeostasis processes, as well as being a cancer-driver mechanism. The development of genome-wide technologies and sophisticated statistical analytical approaches has ushered in an era of widespread analyses, for example in the cancer arena, of the relationships between altered DNA CpG methylation, gene expression, and tumor status...
February 14, 2017: Biomolecules
https://www.readbyqxmd.com/read/28202018/de-novo-biosynthesis-of-pterostilbene-in-an-escherichia-coli-strain-using-a-new-resveratrol-o-methyltransferase-from-arabidopsis
#14
Kyung Taek Heo, Sun-Young Kang, Young-Soo Hong
BACKGROUND: Pterostilbene, a structural analog of resveratrol, has higher oral bioavailability and bioactivity than that of the parent compound; but is far less abundant in natural sources. Thus, to efficiently obtain this bioactive resveratrol analog, it is necessary to develop new bioproduction systems. RESULTS: We identified a resveratrol O-methyltransferase (ROMT) function from a multifunctional caffeic acid O-methyltransferase (COMT) originating from Arabidopsis, which catalyzes the transfer of a methyl group to resveratrol resulting in pterostilbene production...
February 15, 2017: Microbial Cell Factories
https://www.readbyqxmd.com/read/28167035/enzymatic-production-and-emission-of-floral-scent-volatiles-in-jasminum-sambac
#15
Paramita Bera, Chiranjit Mukherjee, Adinpunya Mitra
Floral scent composed of low molecular weight volatile organic compounds. The sweet fragrance of any evening blooming flower is dominated by benzenoid and terpenoid volatile compounds. Floral scent of Jasminum sambac (Oleaceae) includes three major benzenoid esters - benzylacetate, methylbenzoate, and methylsalicylate and three major terpene compounds viz. (E)-β-ocimene, linalool and α-farnesene. We analyzed concentrations and emission rates of benzenoids and terpenoids during the developmental stages of J...
March 2017: Plant Science: An International Journal of Experimental Plant Biology
https://www.readbyqxmd.com/read/28165739/discovery-of-novel-disruptor-of-silencing-telomeric-1-like-dot1l-inhibitors-using-a-target-specific-scoring-function-for-the-s-adenosyl-l-methionine-sam-dependent-methyltransferase-family
#16
Yulan Wang, Linjuan Li, Bidong Zhang, Jing Xing, Shijie Chen, Wei Wan, Yakai Song, Hao Jiang, Hualiang Jiang, Cheng Luo, Mingyue Zheng
The disruptor of telomeric silencing 1-like (DOT1L) protein is a histone H3K79 methyltransferase that plays a key role in transcriptional elongation and cell cycle regulation and is required for the development and maintenance of MLL-rearranged mixed lineage leukemia. Much effort has been dedicated toward discovering novel scaffold DOT1L inhibitors using different strategies. Here, we report the development and application of a target-specific scoring function, the SAM score, for (S)-adenosyl-l-methionine (SAM)-dependent methyltransferases, for the discovery of novel DOT1L inhibitors...
February 21, 2017: Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28152088/crystal-structure-and-catalytic-mechanism-of-couo-a-versatile-c-methyltransferase-from-streptomyces-rishiriensis
#17
Tea Pavkov-Keller, Kerstin Steiner, Mario Faber, Martin Tengg, Helmut Schwab, Mandana Gruber-Khadjawi, Karl Gruber
Friedel-Crafts alkylation of aromatic systems is a classic reaction in organic chemistry, for which regiospecific mono-alkylation, however, is generally difficult to achieve. In nature, methyltransferases catalyze the addition of methyl groups to a wide range of biomolecules thereby modulating the physico-chemical properties of these compounds. Specifically, S-adenosyl-L-methionine dependent C-methyltransferases possess a high potential to serve as biocatalysts in environmentally benign organic syntheses. Here, we report on the high resolution crystal structure of CouO, a C-methyltransferase from Streptomyces rishiriensis involved in the biosynthesis of the antibiotic coumermycin A1...
2017: PloS One
https://www.readbyqxmd.com/read/28140508/identifying-unknown-enzyme-substrate-pairs-from-the-cellular-milieu-with-native-mass-spectrometry
#18
Kalli C Catcott, Jing Yan, Wanlu Qu, Vicki H Wysocki, Zhaohui Sunny Zhou
The enzyme-substrate complex is inherently transient, rendering its detection difficult. In our framework, IsoLAIT (Isotope-Labeled, Activity-based Identification and Tracking), designed for bisubstrate systems, the common substrate, such as S-adenosyl-L-methionine (AdoMet) for methyltransferases, is replaced by an analogue (e.g., S-adenosyl-L-vinthionine) that, as a probe, creates a tightly bound [enzyme*substrate-probe] complex upon catalysis by thiopurine-S-methyltransferase (TPMT, EC 2.1.1.67). Then, this persistent complex is identified by native mass spectrometry from the cellular milieu without separation...
January 31, 2017: Chembiochem: a European Journal of Chemical Biology
https://www.readbyqxmd.com/read/28138060/rna-puzzles-round-iii-3d-rna-structure-prediction-of-five-riboswitches-and-one-ribozyme
#19
Zhichao Miao, Ryszard W Adamiak, Maciej Antczak, Robert T Batey, Alexander J Becka, Marcin Biesiada, Michał J Boniecki, Janusz Bujnicki, Shi-Jie Chen, Clarence Yu Cheng, Fang-Chieh Chou, Adrian R Ferré-D'Amaré, Rhiju Das, Wayne K Dawson, Ding Feng, Nikolay V Dokholyan, Stanisław Dunin-Horkawicz, Caleb Geniesse, Kalli Kappel, Wipapat Kladwang, Andrey Krokhotin, Grzegorz E Łach, François Major, Thomas H Mann, Marcin Magnus, Katarzyna Pachulska-Wieczorek, Dinshaw J Patel, Joseph A Piccirilli, Mariusz Popenda, Katarzyna J Purzycka, Aiming Ren, Greggory M Rice, John Santalucia, Joanna Sarzynska, Marta Szachniuk, Arpit Tandon, Jeremiah J Trausch, Siqi Tian, Jian Wang, Kevin M Weeks, Benfeard Williams, Yi Xiao, Xiaojun Xu, Dong Zhang, Tomasz Zok, Eric Westhof
RNA-Puzzles is a collective experiment in blind 3D RNA structure prediction. We report here a third round of RNA-Puzzles. Five puzzles, 4, 8, 12, 13, 14, all structures of riboswitch aptamers and puzzle 7, a ribozyme structure, are included in this round of the experiment. The riboswitch structures include biological binding sites for small molecules (S-adenosyl methionine, cyclic diadenosine monophosphate, 5-amino 4-imidazole carboxamide riboside 5'-triphosphate, glutamine) and proteins (YbxF) and one set describes large conformational changes between ligand-free and ligand-bound states; the Varkud satellite ribozyme is the most recently solved structure of a known large ribozyme...
January 30, 2017: RNA
https://www.readbyqxmd.com/read/28135835/clinical-use-of-nutraceuticals-in-the-adjunctive-treatment-of-depression-in-mood-disorders
#20
Jerome Sarris
OBJECTIVES: The aim of this paper is to detail a summary of the current evidence in this area, to better inform clinical practice. Our recent systematic reviews and meta-analyses of nutrient pharmacotherapies in the treatment unipolar depression revealed primarily positive results for replicated studies testing S-adenosyl methionine (SAMe), methylfolate, omega-3 (EPA or ethyl-EPA), and Vitamin D; with supportive isolated studies found for creatine and an amino acid combination. Mixed results were found for zinc, folic acid, Vitamin C, and tryptophan; and non-significant study results for inositol...
January 1, 2017: Australasian Psychiatry: Bulletin of Royal Australian and New Zealand College of Psychiatrists
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