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Showing 1 to 20 of 20 for “"ribonucleotides"”.
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Understanding of Intrinsic Sources of DNA Damage that Drive Human Disease: A Foray into the Study of DNA Interstrand Crosslinks and Genome-Embedded Ribonucleotides
… by DNA damaging aldehydes and 2) genome-embedded ribonucleotides. The clinical pathologies arising in the setting of the improper removal or repair of ICLs or genome-embedded ribonucleotides are diverse. A failure to remove ICLs in humans is the cause of Fanconi anemia (FA), a disease …
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Structural Studies of the Mammalian RNase H2 Heterotrimeric Complex
… that specifically catalyze the hydrolysis of ribonucleotides in RNA:DNA hybrids. They are classified into type 1 or type 2 based on amino acid sequence similarity, structure, and biochemical properties. Type 1 RNase Hs require a minimum of four ribonucleotides whereas type 2 can recognize even …
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Functional Roles of Nucleases in DNA Metabolism and Genome Stability
… that remove these noncanonical nucleotides. Ribonucleotides are incorporated into DNA by the replicative DNA polymerases at frequencies of about 2 per kb, which makes them by far the most abundant form of potential DNA damage in the cell. Their removal is essential for restoring a stable …
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DDI1/2 and RTF2-Dependent Regulation of RNASE H2 at the Replisome Ensures Genome Stability
… of RNase H2 and an increase in genome-embedded ribonucleotides, including the accumulation of DNA damage. In the absence of DDI1/2, the persistence of RNase H2 at a stalled replication fork also compromises the replication stress response. We show that direct replication restart is dependent on …
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ADP-Heptose and Nucleotide Enhancers Drive Fusobacteria-Induced Inflammation
… molecular pattern ADP-heptose and ribonucleotides that together, but not individually, strongly induced NF-<em>κ</em>B signaling as well as the expression of inflammation and cancer associated genes. This finding suggests a regulatory role for extracellular nucleotides in …
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Ribonucleotide Reductase Subunit Switching in Hepatoblastoma Drug Response and Relapse
… enzymatic complex in mammal cells that converts ribonucleotides to deoxyribonucleotides and plays a critical role in regulating cell division and DNA repair. We found standard chemotherapy agents as well as two RRM2 inhibitors, triapine and MK1775, werecapable of reducing RRM2 expression …
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Lymphocytopenia in patients with inflammatory bowel disease on immunosuppressive medications
… 6-thioguanine (6TG) and 6-methylmercaptopurine ribonucleotides (6MMP), have been suggested as surrogate markers of the safety and efficacy of immunosuppressive therapy. Elevated levels of 6TG have been found to be associated with bone marrow toxicity manifest as leukopenia. Elevated 6-MMP levels …
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Defining the active form of ribonucleotide reductase from Saccharomyces cerevisiae in vitro and in vivo
… reductase (RNR) catalyzes the conversion of ribonucleotides to deoxyribonucleotides. Saccharomyces cerevisiae RNR is a class I RNR composed of a dimeric large subunit (RI), containing the active site and allosteric effector sites, and a dimeric small subunit (R2) which houses the diferric …
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Chemistry and Regulation of the Oxygen-Dependent Inactivation of Glutamine Phosphoribosyl Pyrophosphate Amidotransferase From Bacillus Subtilis
… to be regulated by relative levels of purine ribonucleotides. The levels of the stabilizer (AMP) and destablizers (GMP + GDP + ADP) will determine the rate of oxygen-dependent inactivation. The model was tested by an examination of changes in the intracellular levels of the regulatory …
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INTEGRATION OF REDOX-REGULATED SIGNALING AND METABOLISM IN HEAD AND NECK CANCER
… pathway for increased production of NADPH, ribonucleotides and endogenous fatty acids, and (3) increased glutathione production, which together with increased NADPH and increased expression of ROS metabolizing enzymes, maintain decreased ROS and coordinate redox regulation of signaling and …
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THE EPITRANSCRIPTOMIC REGULATION OF STRESS: ROLE OF N6-METHYLADENOSINE IN ABIOTIC STRESS RESPONSE
… Covalent modifications of ribonucleotides within the RNA molecules, also known as the epitranscriptome, have recently emerged as an important aspect of post-transcriptional gene regulation. More specifically, studies have shown that N6-methyladenosine(m6A), the most …
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Unifying the features that determine substrate preferences of nanoRNases
… that ultimately replenish the pool of mono-ribonucleotides. While exoribonucleases largely share overlapping substrates and functions, nanoRNases are unique in that they alone degrade short RNA fragments in a process that is essential for cellular fitness. Oligoribonuclease (Orn) was the …
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Kinetics and dynamics controlling proton-coupled electron transfer in ribonucleotide reductase
… in nature. In catalyzing the conversion of ribonucleotides to deoxyribonucleotides, ribonucleotide reductase (RNR) performs reversible, long-range PCET over a pathway of redox active amino acids ([beta]-Y₁₂₂ >/< [beta]-Y₃₅₆ >/< [alpha]-Y₇₃₁ >/< [alpha]-Y₇₃₀ >/< [alpha]-C₄₃₉) that spans ~35 Å …
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Structural studies of allosteric regulation in the class Ia Ribonucleotide reductase from Escherichia coli
Ribonucleotide reductase (RNR) converts ribonucleotides to deoxyribonucleotides, the building blocks for DNA replication and repair. The E. coli class Ia enzyme requires two subunits to catalyze the radical-based reduction reaction. [beta]2 houses a diferric-tyrosyl radical cofactor and [alpha]2 …
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Regulation of the ribonucleotide reductase small subunit gene in Dictyostelium discoideum
… reductase catalyzes the reduction of ribonucleotides to deoxyribonucleotides, providing precursors for the synthesis of DNA. Expression of ribonucleotide reductase is correlated with DNA synthesis: it is up-regulated during the DNA synthesis phase of the cell cycle and in the course of …
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A TALE OF TWO METHYLATION MODIFICATIONS IN ARCHAEAL RNAs
… as well as the ribose sugars of the individual ribonucleotides. 2'-O-methylation of ribose sugars and isomerization of Uridines to Pseudouridines are two most predominant modifications in rRNAs and tRNAs across all domains of life. Besides 2'-O-methylation of ribose sugars, methylation of …
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Functions of RTF2 in DNA Replication and Checkpoint Control
… cells accumulate genomically embedded ribonucleotides. In DDI1/2-depleted cells, retention of RTF2 and RNase H2 at the replication fork leads to inefficient replication restart after fork stalling. We propose that retained RTF2-RNase H2 at the replication fork leads to inefficient RNA …
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Characterization of Bacterial Transcriptional Regulatory Networks through Genome-Wide in vitro Run-Off Transcription RNA-Seq (ROSE)
… is simple and only requires chromosomal DNA, ribonucleotides, RNA polymerase (RNAP) core enzyme, and a specific sigma (σ) factor that recognizes the corresponding promoters that have to be analyzed. ROSE was carried out on Escherichia coli K-12 MG1655 genomic DNA using the E. coli RNAP …
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Studies on the Metabolism of Plant Cells in Tissue Culture
… nucleic acid preparations, mixtures of purified ribonucleotides, or a mixture of tobacco deoxyribo- and ribonucleosides resulting from snake-venom digestion, contained no activity. Deoxyribonucleotides were inhibitory. 14. A ribonucleotide mixture prepared by alkaline hydrolysis of RNA isolated …
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DNA as a functional molecule for control of nanomaterial morphology and for biosensing
… homo-oligomer DNA sequences containing 10 deoxy-ribonucleotides of thymine, adenine, cytosine, or guanine (referred to as T10, A10, C10, and G10, respectively results in the growth of four distinct morphologies. Through detailed kinetic studies by absorption spectroscopy and scanning electron …