scholarly journals Protein tightly bound near the termini of the Physarum extrachromosomal rDNA palindrome.

1981 ◽  
Vol 91 (1) ◽  
pp. 309-314 ◽  
Author(s):  
M K Cheung ◽  
D T Drivas ◽  
V C Littau ◽  
E M Johnson
Keyword(s):  
Molecular Weight ◽  
Organic Solvents ◽  
Ribosomal Rna ◽  
Inverted Repeat ◽  
Gel Electrophoresis ◽  
Physarum Polycephalum ◽  
Chromosomal Integration ◽  
Terminal Protein ◽  
Restriction Fragments ◽  
Repeat Sequences

The genes coding for ribosomal RNa in plasmodia of Physarum polycephalum are arranged palindromically on extrachromosomal rDNA molecules of 61 kb (kilobasepairs). Incubation of mildly extracted rDNA with the 125I Bolton-Hunter reagent results in incorporation of label not removed by SDS, CsCl, or various organic solvents. Labeled protein is preferentially associated with terminal rDNA restriction fragments, as detected after gel electrophoresis of the DNA. Antibody reaction with dinitrophenylated protein-rDNA complexes allows visualization of protein located from 1 to 2 kb from the termini, in a region containing multiple inverted repeat sequences and single-strand gaps. DNase I treatment of either rDNA or rDNA termini releases primarily two labeled protein bands of 5,000 and 13,000 daltons as well as less prominent bands of higher molecular weight. We discuss mechanisms for involvement of terminal protein in replication of 3' ends and chromosomal integration of the rDNA.

scholarly journals MITOCHONDRIAL RNA FROM CULTURED ANIMAL CELLS

1970 ◽  
Vol 46 (2) ◽  
pp. 245-251 ◽  
Author(s):  
Bland S. Montenecourt ◽  
Margaret E. Langsam ◽  
Donald T. Dubin
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Cell Lines ◽  
Ribosomal Rna ◽  
Gel Electrophoresis ◽  
Base Composition ◽  
Size Class ◽  
Mitochondrial Rna ◽  
Animal Cells ◽  
Molecular Weights

Discrete RNA fractions sedimenting slightly slower than 18s ribosomal RNA have been found in mitochondrial preparations from both hamster (BHK-21) and mouse (L-929) cells. This RNA could be separated into two components, present in approximately equimolar amounts, by prolonged zonal centrifugation or acrylamide gel electrophoresis. The hamster components had sedimentation constants averaging 16.8 and 13.4, and molecular weights (estimated by gel electrophoresis) averaging 0.74 and 0.42 x 106 daltons. Mixed labeling experiments showed that the mouse components sedimented and electrophoresed 3–6% more slowly than the corresponding hamster components. The RNA from both cell lines resembled mitochondrial ribosomal RNA from yeast and Neurospora in being GC poor, and in addition the larger and smaller components resembled each other in base composition. These results, taken with those of other recent studies, are compatible with the idea that our high molecular weight mitochondrial RNA is ribosomal; such RNA would then constitute a uniquely small size-class of ribosomal RNA.

A Stable 44S Intermediate in the Autodigestion of 50S Ribosomal Subunits

1971 ◽  
Vol 29 ◽  
pp. 430-431
Author(s):  
John H. Nisbet ◽  
Henry S. Slayter
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Ribosomal Rna ◽  
Gel Electrophoresis ◽  
Type Strain ◽  
Wild Type Strain ◽  
Ribosomal Subunit ◽  
Wild Type ◽  
Ribosomal Subunits ◽  
Type Strains

Wild - type strains of Escherichia coli are known to contain as many as four endogenous nucleases (Ref. 1). These are commonly found associated with the ribosomes after extraction from the cell, but may be removed, with the exception of RNase IV, by washing the ribosomes in NH4Cl (at 0.2 M and higher concentrations). We have examined the effect of these nucleases on the 50S ribosomal subunit of one wild-type strain, K12 (Hfr 3000), by incubating the unwashed particles at 37° in the presence of varying magnesium concentrations.At 10-4 molar magnesium (slower at 10-3 molar), the 50S particle is converted to a species sedimenting at about 44S. About 20% of the total O.D260 is liberated at the same time. Continued incubation leads to the release of more O.D260 material while the RNA remaining in the 44S (Fig. 1) particle is progressively cleaved, eventually to the point where it consists of one principal fragment of molecular weight 0.42 x 106 daltons and several lesser fragments. The ribosomal RNA and proteins have been characterized by acrylamide gel electrophoresis.

Distribution of Inverted Repeat Sequences in Nuclear DNA from Physarum polycephalum

1979 ◽  
Vol 94 (1) ◽  
pp. 179-187 ◽  
Author(s):  
Norman HARDMAN ◽  
Peter L. JACK ◽  
J. P. BROWN ◽  
Alan MCLACHLAN
Keyword(s):  
Inverted Repeat ◽  
Physarum Polycephalum ◽  
Nuclear Dna ◽  
Repeat Sequences

scholarly journals Inheritance of extrachromosomal rDNA in Physarum polycephalum.

1983 ◽  
Vol 3 (4) ◽  
pp. 635-642 ◽  
Author(s):  
P J Ferris ◽  
V M Vogt ◽  
C L Truitt
Keyword(s):  
Inverted Repeat ◽  
Physarum Polycephalum ◽  
Symmetry Axis ◽  
Single Copy ◽  
The Other ◽  
Cleavage Pattern ◽  
Extrachromosomal Dna ◽  
Repeat Sequences ◽  
Rdna Sequences ◽  
Restriction Endonuclease Cleavage

In the acellular slime mold Physarum polycephalum, the several hundred genes coding for rRNA are located on linear extrachromosomal DNA molecules of a discrete size, 60 kilobases. Each molecule contains two genes that are arranged in a palindromic fashion and separated by a central spacer region. We investigated how rDNA is inherited after meiosis. Two Physarum amoebal strains, each with an rDNA recognizable by its restriction endonuclease cleavage pattern, were mated, the resulting diploid plasmodium was induced to sporulate, and haploid progeny clones were isolated from the germinated spores. The type of rDNA in each was analyzed by blotting hybridization, with cloned rDNA sequences used as probes. This analysis showed that rDNA was inherited in an all-or-nothing fashion; that is, progeny clones contained one or the other parental rDNA type, but not both. However, the rDNA did not segregate in a simple Mendelian way; one rDNA type was inherited more frequently than the other. The same rDNA type was also in excess in the diploid plasmodium before meiosis, and the relative proportions of the two rDNAs changed after continued plasmodial growth. The proportion of the two rDNA types in the population of progeny clones reflected the proportion in the parent plasmodium before meoisis. The rDNAs in many of the progeny clones contained specific deletions of some of the inverted repeat sequences at the central palindromic symmetry axis. To explain the pattern of inheritance of Physarum rDNA, we postulate that a single copy of rDNA is inserted into each spore or is selectively replicated after meiosis.

scholarly journals Sequence organization in nuclear deoxyribonucleic acid from Physarum polycephalum. Physical properties of foldback sequences

1980 ◽  
Vol 187 (1) ◽  
pp. 105-113 ◽  
Author(s):  
P L Jack ◽  
N Hardman
Keyword(s):  
Inverted Repeat ◽  
Physarum Polycephalum ◽  
Nuclear Dna ◽  
Single Copy ◽  
Dna Molecules ◽  
Single Chain ◽  
Sequence Organization ◽  
Repeat Sequences ◽  
Salt Gradient ◽  
Average Size

An investigation was performed with the use of physical techniques, to determine the nature and organization of inverted repeat sequences in nuclear DNA fragments from Physarum polycephalum. From the average size of foldback duplexes (550 nucleotide pairs), and the foldback duplex yield as determined by treatment of DNA with S1 deoxyribonuclease followed by hydroxyapatite chromatography, it is estimated that there are at least 25000 foldback sequences in the Physarum genome. Foldback DNA molecules exhibit properties intermediate between single-stranded DNA and native duplexes on elution from hydroxyapatite with a salt gradient. In addition, thermal-elution chromatography of foldback DNA from hydroxyapatite crystals shows that foldback duplexes are less stable than native DNA. These properties can be explained on the basis that inverted repeat sequences are mismatched when in the foldback configuration. The results of experiments in which the binding of foldback DNA molecules to hydroxyapatite was determined, by using fragments of different single-chain size, agree with previous studies indicating that inverted repeat sequences are located, on average, every 7000 residues throughout the Physarum genome. The inverted repeats are derived from both the repetitive and single-copy components in Physarum nuclear DNA.

Inheritance of extrachromosomal rDNA in Physarum polycephalum

1983 ◽  
Vol 3 (4) ◽  
pp. 635-642
Author(s):  
P J Ferris ◽  
V M Vogt ◽  
C L Truitt
Keyword(s):  
Inverted Repeat ◽  
Physarum Polycephalum ◽  
Symmetry Axis ◽  
Single Copy ◽  
The Other ◽  
Cleavage Pattern ◽  
Extrachromosomal Dna ◽  
Repeat Sequences ◽  
Rdna Sequences ◽  
Restriction Endonuclease Cleavage

In the acellular slime mold Physarum polycephalum, the several hundred genes coding for rRNA are located on linear extrachromosomal DNA molecules of a discrete size, 60 kilobases. Each molecule contains two genes that are arranged in a palindromic fashion and separated by a central spacer region. We investigated how rDNA is inherited after meiosis. Two Physarum amoebal strains, each with an rDNA recognizable by its restriction endonuclease cleavage pattern, were mated, the resulting diploid plasmodium was induced to sporulate, and haploid progeny clones were isolated from the germinated spores. The type of rDNA in each was analyzed by blotting hybridization, with cloned rDNA sequences used as probes. This analysis showed that rDNA was inherited in an all-or-nothing fashion; that is, progeny clones contained one or the other parental rDNA type, but not both. However, the rDNA did not segregate in a simple Mendelian way; one rDNA type was inherited more frequently than the other. The same rDNA type was also in excess in the diploid plasmodium before meiosis, and the relative proportions of the two rDNAs changed after continued plasmodial growth. The proportion of the two rDNA types in the population of progeny clones reflected the proportion in the parent plasmodium before meoisis. The rDNAs in many of the progeny clones contained specific deletions of some of the inverted repeat sequences at the central palindromic symmetry axis. To explain the pattern of inheritance of Physarum rDNA, we postulate that a single copy of rDNA is inserted into each spore or is selectively replicated after meiosis.

II. Isolierung und Charakterisierung der Chloroplasten-Ribosomen von Antirrhinum majus

1968 ◽  
Vol 23 (7) ◽  
pp. 997-1004 ◽  
Author(s):  
Hans Georg Ruppel
Keyword(s):  
Molecular Weight ◽  
Serum Albumin ◽  
High Molecular Weight ◽  
Ribosomal Rna ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Molecular Size ◽  
Antirrhinum Majus ◽  
Low Molecular Weight ◽  
Fraction I

Methods for very efficient isolation of non-degraded chloroplasts from Antirrhinum majus are described. When studied in the analytical ultracentrifuge, isolated ribosomes of such chloroplasts show a single symmetrical 68s peak. Extraction of the ribosomal RNA from chloroplasts and chromatographic separation on methylated serum albumin yields 4 main fractions: (1) low molecular weight RNA (fraction I b) with s20 = 5.5, (2) high molecular weight RNA (fraction III) with s20 = 16-17, (3) high molecular weight RNA (fraction V) with s20 = 23, and (4) a RNA fraction (fraction VI) heterogeneous in molecular size. In addition data are presented which show a higher resolution of RNA species by polyacrylamide gel electrophoresis than by chromatographic fractionation on methylated serum albumin. The high molecular weight RNA (16 -17s) of chloroplasts differs from the corresponding “light” ribosomal RNA of the cytoplasm in its electrophoretic mobility.

Heterozygous Abnormal Fibrinogen Osaka III with the Replacement of γ Arginine-275 by Histidine Has an Apparently Higher Molecular Weight γ-Chain Variant

1992 ◽  
Vol 68 (05) ◽  
pp. 534-538 ◽  
Author(s):  
Nobuhiko Yoshida ◽  
Shingi Imaoka ◽  
Hajime Hirata ◽  
Michio Matsuda ◽  
Shinji Asakura
Keyword(s):  
Molecular Weight ◽  
Sodium Dodecyl Sulfate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Tetraacetic Acid ◽  
Fibrin Monomer ◽  
Sds Page ◽  
Thrombotic Tendency ◽  
Chain Variant

SummaryCongenitally abnormal fibrinogen Osaka III with the replacement of γ Arg-275 by His was found in a 38-year-old female with no bleeding or thrombotic tendency. Release of fibrinopeptide(s) by thrombin or reptilase was normal, but her thrombin or reptilase time in the absence of calcium was markedly prolonged and the polymerization of preformed fibrin monomer which was prepared by the treatment of fibrinogen with thrombin or reptilase was also markedly defective. Propositus' fibrinogen had normal crosslinking abilities of α- and γ-chains. Analysis of fibrinogen chains on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the system of Laemmli only revealed the presence of abnormal γ-chain with an apparently higher molecular weight, the presence of which was more clearly detected with SDS-PAGE of fibrin monomer obtained by thrombin treatment. Purified fragment D1 of fibrinogen Osaka III also seemed to contain an apparently higher molecular weight fragment D1 γ remnant on Laemmli gels, which was digested faster than the normal control by plasmin in the presence of [ethy-lenebis(oxyethylenenitrilo)]tetraacetic acid (EGTA).

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