Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Polynucleotide kinase (ATP:5'-dephosphopolynucleotide 5'-phosphotransferase, EC 2.7.1.78) has been purified approx. 1500-fold from calf thymus. This enzyme phosphorylates 5'-hydroxyl termini in DNA using ATP as phosphate donor. RNA is phosphorylated at a much lower rate than DNA. The reaction requires the presence of a divalent cation, preferably Mg2+ or Mn2+ and is sensitive to sulfhydryl antagonists. The optimum pH for enzyme activity is 5.5. Enzyme activity is inhibited by low concentrations of inorganic sulfate and by some sulfate polymers. The kinase-catalyzed incorporation of the terminal phosphate of ATP into polynucleotides is inhibited by other nucleoside and deoxynucleoside triphosphates. The enzyme molecule has a molecular weight of about 70 000 and a Stokes radius of 4.3 nm. It has a frictional ratio of 1.44 indicating an asymmetrical structure. Calf thymus tissue should provide a useful alternative source for preparation of mammalian polynucleotide kinase.
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PMID:Purification and properties of polynucleotide kinase of calf thymus. 2 43

Seven cases of confirmed or probable acute necrotizing herpes encephalitis (ANE) were studied using computer tomography during the various acute or chronic stages of the disease. They were bilateral, or in some rare patients, asymmetrical pseudofocal cases of ANE. Computer tomography appearances are described from the morphological and topographical point of view, before and after intravenous injection of a contrast medium. Analogous data reported in the published literature is used to describe the findings and to emphasize the problem of differential diagnosis. Computer tomography appears to be an essential examination for establishing the diagnosis and prognosis in herpes encephalitis, but it must be correlated with the results of an electro-encephalogram, and biological and immunological tests of the cerebrospinal fluid. It can also be of value for choosing the optimal site for urgent cerebral biopsy with immunofluorescence. Treatment must be given very early, whether Ara A antiviral DNA or Isoprinosine (Inosiplex) which stimulates cellular immunity, as soon after diagnosis has been established as possible. The authors chose the latter medication for 6 of the 7 cases reported, as well as in 12 other cases of acute primary viral encephalitis, and 3 cases of subacute sclerozing panencephalitis, and obtained very positive results.
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PMID:[C.T. scan appearances of acute necrotizing herpes encephalitis (7 cases). Preliminary therapeutic results after isoprinosine (author's transl)]. 9 73

From a consideration of the various structural forms of partially replicated mitochondrial DNA (mtDNA) molecules from Drosophila melanogaster embryos observed in the electron microscope, it appears that the majority of molecules are replicated by a highly asymmetrical mode in which synthesis on one strand is up to 99% complete before synthesis on the second strand is initiated. Replication of the minority of molecules involves a more nearly symmetrical synthesis of the two complementary strands. The D. melanogaster mtDNA molecules have physical features with respect to which the origin and direction of replication could be mapped. These features are (i) a single region accounting for approximately 25% of the circular contour length and rich in adenine + thymine, and (ii) four EcoRI sites, all of which lie outside of this region. Molecules of this mtDNA were subjected to partial denaturation, EcoRI digestion, or partial denaturation after EcoRI digestion and the products were examined in the electron microscope. Complex forms interpretable as originating from replicative intermediates were observed. The size and structure of the components of these complex forms were wholly consistent with the interpretation that, in all of these mtDNA molecules, replication originates at, or close to, the center of the adenine + thymine-rich region and proceeds unidirectionally around the molecule toward the EcoRI site lying closest to the adenine + thymine-rich region.
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PMID:Origin and direction of replication in mitochondrial DNA molecules from Drosophila melanogaster. 9 43

The sequence complexity of nuclear RNA from mouse liver, mouse spleen and highly malignant P815 mastocytoma was measured by nRNA driven hybridization to unique DNA sequences of P815 cells. The unique DNA sequences represent 63% of the total nuclear DNA of P815 cells and their availibility in hybridization experiments was found to be 76%. Of these sequences 7.8% formed hybrids with nuclear RNA of this cell, about 11.5% with mouse spleen and about 14.5% with mouse liver nuclear RNA. Assuming an asymmetrical transcription, the complexities of these transcripts are 2.8 X 10(8) nucleotides for mouse P815 mastocytomas, 4.3 X 10(8) for mouse spleen and about 5.3 X 10(8) nucleotides for mouse liver. Cellular specifity of the transcribed information was analyzed in additivity experiments, in which unique DNA sequences, not complementary to the nuclear RNA of one cell were annealed to the nuclear RNAs of the two other tissues/cells. In these experiments most of the nuclear RNA sequences of P815 cells were found to be also present in the nucleus of mouse liver and spleen. Only a small portion of the unique DNA sequences of P815 mastocytoma (about 1.2% corresponding to 4.4 X 10(7) nucleotides) was found to be complementary only to P815 mastocytoma nuclear RNA.
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PMID:[Sequence complexity of transcribed unique DNA sequences in genome of mouse P815 mastocytoma cells (author's transl)]. 15 3

H1 protein, a heat-stable low-molecular-weight DNA-binding factor previously described by Cukier-Kahn et al. [Proc. Nat. Acad. Sci USA (1972) 69, 3643-3647] markedly stimulates in vitro synthesis of lac-specific RNA directed by bacteriophage lambdah80 dlac or phi80 dlac DNA templates in the presence of purified E. coli RNA polymerase holoenzyme. The extent of stimulation obtained by addition of H1 alone is usually greater than that observed with the cAMP receptor protein-cAMP combination. H1 effect varies quite appreciably (from 4- to 16-fold) with the functional state of the promoter, being much larger with lambdah80 dlac p-s, a transducing DNA carrying a superpromoter mutation, than with lambdah80 dlac p+. H1 and cAMP receptor protein effects are nearly additive, although interpretation of the data obtained at high H1 concentration is complicated by the appearance of some inhibitory property. While the cAMP-receptor-protein-mediated synthesis is asymmetrical ("I" strand almost exclusively copied), the degree of asymmetry observed with H1 is less pronounced, suggesting asymmetrical copying from the lac promoter and symmetric transcription from other regions of the DNA. Synthesis of lac-specific RNA from lambdah80 dtrp/lac or phi80 dlac p-r uv5 templates, in which lac promoters are insensitive to cAMP receptor protein, either as a result of lac fusion to the trp operon or mutation in the lac promoter, is totally H1-insensitive. Glycerol (10-15% w/w) can fully substitute for H1 in stimulating lac RNA synthesis in a fashion analogous to that reported for the cAMP receptor protein-cAMP system. The possibility that H1 acts by causing conformational modifications at the promoter level in a way that increases its functional state, and that this effect is more pronounced with operons sensitive to cAMP receptor protein, is discussed.
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PMID:Effect of a low-molecular-weight DNA binding protein, H1 factor, on the in vitro transcription of the lactose operon in Escherichia coli. 16 21

Electron spin resonance study of Mn (II) binding to chromatin and derivatives, including core particles, shows that Mn (II) is a good probe for testing the overall electrostatic balance of the nucleoproteic complex as well as DNA accessibility. Experimental results are in good agreement with a recent model proposed (Mirzabekov A. D. and Rich A. (1979) Proc. Natl. Acad. Sci. USA 76, 1118-1121), for the core particle, in which an asymmetrical shielding of DNA by the protein core is assumed. Furthermore, it was found that the histone H1 hinders a number of charges on the linker DNA in a proportion equal to the net positive charge of the histone itself. This result is interpreted as due to a tighter interaction between the linker DNA and the core histones in the presence of histone H1.
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PMID:Experimental evidence for asymmetrical shielding of nucleosomal DNA by histones. 23 Apr 66

Addition of diadenosine 5',5'''-P1,P4-tetraphosphate (Ap4A) to permeabilized G1-arrested baby hamster kidney cells resulted in the stimulation of DNA synthesis. No stimulation was observed in cells from exponentially growing cultures. The Ap4A-stimulated [3H]dTTP incorporation was inhibited by nalidixic acid, daunomycin, chloroquine diphosphate, EDTA, and N-ethylmaleimide. It was dose-dependent in regard to the amount of permeabilized cells and of Ap4A. Numerous replication eyes were formed in the DNA molecules of stimulated cells. Pulse-chase experiments showed that the synthesis of DNA was discontinuous, resulting in the appearance of approximately 4S Okazaki fragments and their ligation to high molecular weight DNA. These results strongly suggest that Ap4A stimulated the initiation of DNA synthesis in baby hamster kidney cells that had been arrested in G1 by serum deprival.
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PMID:Diadenosine 5',5'''-P1,P4-tetraphosphate triggers initiation of in vitro DNA replication in baby hamster kidney cells. 27 52

Karyotypes have been studied in 3 species of Hynobius and in 1 species each of the remaining genera of Hynobiids (Ranodon, Batrachuperus, Salamandrella and Onychodactylus). All species have large diploid numbers, between 56 and 66, and asymmetrical and bimodal karyotypes. DNA contents (2C) were found to vary between 33 and 51 pg. Determination was not possible in Onychodactylus where higher values may be suspected. Some of the karyotypes investigated are similar to those of Cryptobranchids. Phylogenetic implications are discussed.
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PMID:Karyology of the primitive salamanders, family Hynobiidae. 51 Apr 68

Crosses were made between strains carrying a nuclear control factor (NC) and strains classified with respect to their omega allele (omega+ or omega-). The characteristic asymmetrical transmission was always observed (as was seen) in crosses not involving the omega factor. The analysis of functional recombinants in a cross involving an NC factor has indicated that the absence of the omega effect may be caused by a restriction in the zygote of the recombination of mitochondrial DNA molecules.
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PMID:The restriction of the recombination of mitochondrial DNA molecules in the zygotes of Saccharomyces cerevisiae. 76 28

A study was made of morphology, character and the rate of reproduction in 8 11r mutants obtained from Hfr and F--strains of E. coli K12 under the effect of N-nitroso-N-methylurea. The capacity of 11r mutants to realize several types of reproduction: transverse division, budding, asymmetrical division, and formation of granular forms was demonstrated. The rate of cell division, total DNA, RNA and protein synthesis were lower at the phase of rest and early exponential growth phase in the 11r mutants than in the parent cultures. Hyperosmotic conditions created by various stabilizers, media with increased viscosity and of different chemical composition, and also cell wall hydrolysate and their precursors failed to stimulate the 11r mutant reversion. A change of morphology, but not the reversion was seen on the media containing glycine and penicillin. Reversion was spontaneous with low frequency; it was observed in induction of inverse mutations with N-nitroso-N-methylurea.
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PMID:[Morphological and physiological peculiarities of spherical (11r) mutants of Escherichia coli K12]. 79 39


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