keyword
MENU ▼
Read by QxMD icon Read
search

riboswitch

keyword
https://www.readbyqxmd.com/read/28719589/an-excited-state-underlies-gene-regulation-of-a-transcriptional-riboswitch
#1
Bo Zhao, Sharon L Guffy, Benfeard Williams, Qi Zhang
Riboswitches control gene expression through ligand-dependent structural rearrangements of the sensing aptamer domain. However, we found that the Bacillus cereus fluoride riboswitch aptamer adopts identical tertiary structures in solution with and without ligand. Using chemical-exchange saturation transfer (CEST) NMR spectroscopy, we revealed that the structured ligand-free aptamer transiently accesses a low-populated (∼1%) and short-lived (∼3 ms) excited conformational state that unravels a conserved 'linchpin' base pair to signal transcription termination...
July 17, 2017: Nature Chemical Biology
https://www.readbyqxmd.com/read/28718632/systematic-approaches-to-efficiently-produce-2-3-butanediol-in-a-marine-cyanobacterium
#2
Nicole E Nozzi, Anna E Case, Austin L Carroll, Shota Atsumi
Cyanobacteria have attracted significant interest as a platform for renewable production of fuel and feedstock chemicals from abundant atmospheric carbon dioxide by way of photosynthesis. While great strides have been made in developing this technology in freshwater cyanobacteria, logistical issues remain in scale-up. Use of the cyanobacterium Synechococcus sp. PCC 7002 (7002) as a chemical production chassis could address a number of these issues given the higher tolerance to salt, light, and heat as well as the fast growth rate of 7002 in comparison to traditional model cyanobacteria such as Synechococcus elongatus PCC 7942 and Synechocystis sp...
July 18, 2017: ACS Synthetic Biology
https://www.readbyqxmd.com/read/28701520/ligand-recognition-and-helical-stacking-formation-are-intimately-linked-in-the-sam-i-riboswitch-regulatory-mechanism
#3
Anne-Marie Dussault, Audrey Dubé, Frédéric Jacques, Jonathan P Grondin, Daniel Lafontaine
Riboswitches are non-coding mRNA elements that control gene expression by altering their structure upon metabolite binding. Although riboswitch crystal structures provide detailed information about RNA-ligand interactions, little knowledge has been gathered to understand how riboswitches modulate gene expression. Here, we study the molecular recognition mechanism of the S-adenosylmethionine SAM-I riboswitch by characterizing the formation of a helical stacking interaction involving the ligand binding process...
July 12, 2017: RNA
https://www.readbyqxmd.com/read/28691825/small-molecule-recognition-triggers-secondary-and-tertiary-interactions-in-dna-folding-and-hammerhead-ribozyme-catalysis
#4
Jie Mao, Chris DeSantis, Dennis Bong
We have identified tris(2-aminoethyl)amine (tren)-derived scaffolds with two (t2M) or four (t4M) melamine rings that can target oligo T/U domains in DNA/RNA. Unstructured T-rich DNAs cooperatively fold with the tren derivatives to form hairpin-like structures. Both t2M and t4M act as functional switches in a family of hammerhead ribozymes deactivated by stem or loop replacement with a U-rich sequence. Catalysis of bond scission in these hammerhead ribozymes could be restored by putative t2M/t4M refolding of stem secondary structure or tertiary bridging interactions between loop and stem...
July 13, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28676696/ribo-attenuators-novel-elements-for-reliable-and-modular-riboswitch-engineering
#5
Thomas Folliard, Barbara Mertins, Harrison Steel, Thomas P Prescott, Thomas Newport, Christopher W Jones, George Wadhams, Travis Bayer, Judith P Armitage, Antonis Papachristodoulou, Lynn J Rothschild
Riboswitches are structural genetic regulatory elements that directly couple the sensing of small molecules to gene expression. They have considerable potential for applications throughout synthetic biology and bio-manufacturing as they are able to sense a wide range of small molecules and regulate gene expression in response. Despite over a decade of research they have yet to reach this considerable potential as they cannot yet be treated as modular components. This is due to several limitations including sensitivity to changes in genetic context, low tunability, and variability in performance...
July 4, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28661578/fluoro-carba-sugars-are-glycomimetic-activators-of-the-glms-ribozyme
#6
Günter Mayer, Daniel Matzner, Anna Schüller, Torben Seitz, Valentin Wittmann
The glmS ribozyme is a bacterial gene-regulating riboswitch that controls cell wall synthesis, depending on glucosamine-6-phosphate as a cofactor. Due to the presence of this ribozyme in several human pathogen bacteria (e.g. MRSA, VRSA), the glmS ribozyme represents an attractive target for the development of artificial cofactors. The substitution of the ring oxygen in carbohydrates by functionalized methylene groups leads to a new generation of glycomimetics that exploits distinct interaction possibilities with their target structure in biological systems...
June 29, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28640851/ligand-mediated-and-tertiary-interactions-cooperatively-stabilize-the-p1-region-in-the-guanine-sensing-riboswitch
#7
Christian A Hanke, Holger Gohlke
Riboswitches are genetic regulatory elements that control gene expression depending on ligand binding. The guanine-sensing riboswitch (Gsw) binds ligands at a three-way junction formed by paired regions P1, P2, and P3. Loops L2 and L3 cap the P2 and P3 helices and form tertiary interactions. Part of P1 belongs to the switching sequence dictating the fate of the mRNA. Previous studies revealed an intricate relationship between ligand binding and presence of the tertiary interactions, and between ligand binding and influence on the P1 region...
2017: PloS One
https://www.readbyqxmd.com/read/28640671/regulation-of-a-muralytic-enzyme-encoding-gene-by-two-non-coding-rnas
#8
Renée J St-Onge, Marie A Elliot
Non-coding regulatory RNAs fine-tune gene expression post-transcriptionally. In the streptomycetes, rpfA - encoding a muralytic enzyme required for establishing and exiting dormancy - is flanked by non-coding regulatory RNA elements both upstream (riboswitch) and downstream [antisense small RNA (sRNA)]. In Streptomyces coelicolor, the upstream riboswitch decreases rpfA transcript abundance in response to the second messenger cyclic di-AMP, itself involved in cell wall metabolism and dormancy. There is, however, no obvious expression platform associated with this riboswitch and consequently, its mechanism of action is entirely unknown...
June 22, 2017: RNA Biology
https://www.readbyqxmd.com/read/28625696/comparative-visualization-of-the-rna-suboptimal-conformational-ensemble-in%C3%A2-vivo
#9
Chanin T Woods, Lela Lackey, Benfeard Williams, Nikolay V Dokholyan, David Gotz, Alain Laederach
When a ribonucleic acid (RNA) molecule folds, it often does not adopt a single, well-defined conformation. The folding energy landscape of an RNA is highly dependent on its nucleotide sequence and molecular environment. Cellular molecules sometimes alter the energy landscape, thereby changing the ensemble of likely low-energy conformations. The effects of these energy landscape changes on the conformational ensemble are particularly challenging to visualize for large RNAs. We have created a robust approach for visualizing the conformational ensemble of RNAs that is well suited for in vitro versus in vivo comparisons...
June 15, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28621923/capture-and-release-of-trna-by-the-t-loop-receptor-in-the-function-of-the-t-box-riboswitch
#10
Xianyang Fang, Malgorzata Michnicka, Yikan Zhang, Yun-Xing Wang, Edward P Nikonowicz
In Gram-positive bacteria, the tRNA-dependent T-box riboswitch system regulates expression of amino acid biosynthetic and aminoacyl-tRNA synthetase genes through a transcription attenuation mechanism. Binding of uncharged tRNA "closes" the switch, allowing transcription read-through. Structural studies of the 100-nucleotide stem I domain reveal tRNA utilizes base pairing and stacking interactions to bind the stem, but little is known structurally about the 180-nucleotide riboswitch core (stem I, stem III, and antiterminator stem) in complex with tRNA or the mechanism of coupling of the intermolecular binding domains crucial to T-box function...
July 18, 2017: Biochemistry
https://www.readbyqxmd.com/read/28613837/artificial-off-riboswitches-that-downregulate-internal-ribosome-entry-without-hybridization-switches-in-a-eukaryotic-cell-free-translation-system
#11
Atsushi Ogawa, Hiroki Masuoka, Tsubasa Ota
We constructed novel artificial riboswitches that function in a eukaryotic translation system (wheat germ extract), by rationally implanting an in vitro-selected aptamer into the intergenic internal ribosome entry site (IRES) of Plautia stali intestine virus. These eukaryotic OFF-riboswitches (OFF-eRSs) ligand-dose-dependently downregulate IRES-mediated translation without hybridization switches, which typical riboswitches utilize for gene regulation. The hybridization-switch-free mechanism not only allows for easy design but also requires less energy for regulation, resulting in a higher switching efficiency than hybridization-switch-based OFF-eRSs provide...
June 14, 2017: ACS Synthetic Biology
https://www.readbyqxmd.com/read/28611182/the-lost-language-of-the-rna-world
#12
REVIEW
James W Nelson, Ronald R Breaker
The possibility of an RNA World is based on the notion that life on Earth passed through a primitive phase without proteins, a time when all genomes and enzymes were composed of ribonucleic acids. Numerous apparent vestiges of this ancient RNA World remain today, including many nucleotide-derived coenzymes, self-processing ribozymes, metabolite-binding riboswitches, and even ribosomes. Many of the most common signaling molecules and second messengers used by modern organisms are also formed from RNA nucleotides or their precursors...
June 13, 2017: Science Signaling
https://www.readbyqxmd.com/read/28609710/sense-and-sensitivity-in-bioprocessing-detecting-cellular-metabolites-with-biosensors
#13
REVIEW
Linda Dekker, Karen M Polizzi
Biosensors use biological elements to detect or quantify an analyte of interest. In bioprocessing, biosensors are employed to monitor key metabolites. There are two main types: fully biological systems or biological recognition coupled with physical/chemical detection. New developments in chemical biosensors include multiplexed detection using microfluidics. Synthetic biology can be used to engineer new biological biosensors with improved characteristics. Although there have been few biosensors developed for bioprocessing thus far, emerging trends can be applied in the future...
June 10, 2017: Current Opinion in Chemical Biology
https://www.readbyqxmd.com/read/28600356/structural-basis-for-ligand-binding-to-the-guanidine-ii-riboswitch
#14
Caroline W Reiss, Scott A Strobel
The guanidine-II riboswitch, also known as mini-ykkC, is a conserved mRNA element with more than 800 examples in bacteria. It consists of two stemloops capped by identical, conserved tetraloops that are separated by a linker region of variable length and sequence. Like the guanidine-I riboswitch, it controls the expression of guanidine carboxylases and SugE-like genes. The guanidine-II riboswitch specifically binds free guanidinium cation and functions as a translationally-controlled on-switch. Here we report the structure of a P2 stemloop from the Pseudomonas aeruginosa guanidine-II riboswitch aptamer bound to guanidine at 1...
June 9, 2017: RNA
https://www.readbyqxmd.com/read/28591515/roc-n-ribo-characterizing-a-riboswitching-expression-system-by-modeling-single-cell-data
#15
Christopher Schneider, Leo Bronstein, Jascha Diemer, Heinz Koeppl, Beatrix Suess
RNA-engineered systems offer simple and versatile control over gene expression in many organisms. In particular, the design and implementation of riboswitches presents a unique opportunity to manipulate any reporter device in cis, executing tight temporal and spatial control at low metabolic costs. Assembled to higher order genetic circuits, such riboswitch-regulated devices may efficiently process logical operations. Here, we propose a hierarchical stochastic modeling approach to characterize an in silico repressor gate based on neomycin- and tetracycline-sensitive riboswitches...
June 30, 2017: ACS Synthetic Biology
https://www.readbyqxmd.com/read/28572834/stream-formula-see-text-algorithms-for-analyzing-coarse-grained-rna-dynamics-based-on-markov-models-of-connectivity-graphs
#16
Sven Jager, Benjamin Schiller, Philipp Babel, Malte Blumenroth, Thorsten Strufe, Kay Hamacher
BACKGROUND: In this work, we present a new coarse grained representation of RNA dynamics. It is based on adjacency matrices and their interactions patterns obtained from molecular dynamics simulations. RNA molecules are well-suited for this representation due to their composition which is mainly modular and assessable by the secondary structure alone. These interactions can be represented as adjacency matrices of k nucleotides. Based on those, we define transitions between states as changes in the adjacency matrices which form Markovian dynamics...
2017: Algorithms for Molecular Biology: AMB
https://www.readbyqxmd.com/read/28559057/synthesis-and-evaluation-of-c-di-4-thioamp-as-an-artificial-ligand-for-c-di-amp-riboswitch
#17
Kazuto Shiraishi, Noriko Saito-Tarashima, Yosuke Igata, Keiji Murakami, Yasuko Okamoto, Yoichiro Miyake, Kazuhiro Furukawa, Noriaki Minakawa
Cyclic-di-adenosine monophosphate (c-di-AMP) is a bacterial second messenger that binds to an RNA receptor called riboswitch and regulates its downstream genes involving cell wall metabolism, ion transport, and spore germination. Therefore, the c-di-AMP riboswitch can be a novel target of antibiotics. In this study, we synthesized c-di-4'-thioAMP (1), which possesses a sulfur atom instead of an oxygen atom in the furanose ring, as a candidate of a bioisoster for natural c-di-AMP. The resulting 1 bound to the c-di-AMP riboswitch with a micromolar affinity (34...
May 20, 2017: Bioorganic & Medicinal Chemistry
https://www.readbyqxmd.com/read/28552565/production-of-amino-acids-genetic-and-metabolic-engineering-approaches
#18
REVIEW
Jin-Ho Lee, Volker F Wendisch
The biotechnological production of amino acids occurs at the million-ton scale and annually about 6milliontons of l-glutamate and l-lysine are produced by Escherichia coli and Corynebacterium glutamicum strains. l-glutamate and l-lysine production from starch hydrolysates and molasses is very efficient and access to alternative carbon sources and new products has been enabled by metabolic engineering. This review focusses on genetic and metabolic engineering of amino acid producing strains. In particular, rational approaches involving modulation of transcriptional regulators, regulons, and attenuators will be discussed...
May 15, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28543037/naringenin-responsive-riboswitch-based-fluorescent-biosensor-module-for-escherichia-coli-co-cultures
#19
Yu Xiu, Sungho Jang, J Andrew Jones, Nicholas A Zill, Robert J Linhardt, Qipeng Yuan, Gyoo Yeol Jung, Mattheos A G Koffas
The ability to design and construct combinatorial synthetic metabolic pathways has far exceeded our capacity for efficient screening and selection of the resulting microbial strains. The need for high-throughput rapid screening techniques is of upmost importance for the future of synthetic biology and metabolic engineering. Here we describe the development of a RNA riboswitch-based biosensor module with dual fluorescent reporters, and demonstrate a high-throughput flow cytometry-based screening method for identification of naringenin over producing Escherichia coli strains in co-culture...
May 20, 2017: Biotechnology and Bioengineering
https://www.readbyqxmd.com/read/28541183/pausing-guides-rna-folding-to-populate-transiently-stable-rna-structures-for-riboswitch-based-transcription-regulation
#20
Hannah Steinert, Florian Sochor, Anna Wacker, Janina Buck, Christina Helmling, Fabian Hiller, Sara Keyhani, Jonas Noeske, Steffen Grimm, Martin M Rudolph, Heiko Keller, Rachel Anne Mooney, Robert Landick, Beatrix Suess, Boris Fürtig, Jens Wöhnert, Harald Schwalbe
In bacteria, the regulation of gene expression by cis-acting transcriptional riboswitches located in the 5'-untranslated regions of messenger RNA requires the temporal synchronization of RNA synthesis and ligand binding-dependent conformational refolding. Ligand binding to the aptamer domain of the riboswitch induces premature termination of the mRNA synthesis of ligand-associated genes due to the coupled formation of 3'-structural elements acting as terminators. To date, there has been no high resolution structural description of the concerted process of synthesis and ligand-induced restructuring of the regulatory RNA element...
May 25, 2017: ELife
keyword
keyword
82702
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"