The Effect of Magnesium Ion on the Secondary Structure of Deoxyribonucleic Acid

1965 ◽  
Vol 87 (8) ◽  
pp. 1781-1785 ◽  
Author(s):  
John W. Lyons ◽  
Leonard Kotin
Keyword(s):  
Secondary Structure ◽  
Deoxyribonucleic Acid ◽  
Magnesium Ion

scholarly journals AMINOACRIDINE DYES AND THE SECONDARY STRUCTURE OF DNA IN SITU

1971 ◽  
Vol 19 (12) ◽  
pp. 761-765 ◽  
Author(s):  
MANUEL DIAZ ◽  
JOSE HIERRO ◽  
GRACIELA DEMICHELI DE DIAZ
Keyword(s):  
Secondary Structure ◽  
Acid Solution ◽  
Nitrous Acid ◽  
Deoxyribonucleic Acid ◽  
New Method ◽  
Green Fluorescence ◽  
Double Stranded Dna

A new method is proposed to study the secondary structure of deoxyribonucleic acid (DNA) in situ in fixed chromatin. It is based on acriflavine staining and on differentiation with a nitrous acid solution of the fixed cytologic preparation. The presence of green fluorescence after this treatment is regarded as indicative of double stranded DNA. Experiments are described with DNA-acriflavine mixtures in solution, DNA-agar models and cytologic preparations submitted to different pretreatments. The feasibility and limitations of the method are discussed in the light of the results reported upon.

Extracellular nuclease produced by a marine bacterium. I. Extracellular deoxyribonuclease formation by a marine Vibrio sp.

1976 ◽  
Vol 22 (10) ◽  
pp. 1437-1442 ◽  
Author(s):  
M. Maeda ◽  
N. Taga
Keyword(s):  
Marine Bacterium ◽  
Deoxyribonucleic Acid ◽  
Culture Liquid ◽  
Dnase Activity ◽  
Magnesium Ion ◽  
Optimum Temperature ◽  
Deficient Medium ◽  
Marine Vibrio ◽  
Extracellular Nuclease ◽  
Marine Vibrio Sp

Deoxyribonuclease (DNase) activity was found in the culture fluids of numerous marine bacteria isolated from seawater. Among these organisms, marine bacterium, Vibrio sp., strain No. 2, showed the highest deoxyribonucleic acid – hydrolyzing activity. This organism requires salts of seawater for both growth and extracellular DNase formation. The DNase activity could not be detected in the synthetic seawater culture liquid lacking magnesium ion, and DNase activity decreased in a calcium-deficient medium. The optimum temperature for the growth of this organism was between 15 and 25 °C. The formation of extracellular DNase was the greatest at 20 °C and less activity was found at 10 and 30 °C.

scholarly journals The effects of deoxyribonucleic acid secondary structure on tertiary structure

1976 ◽  
Vol 159 (3) ◽  
pp. 615-620 ◽  
Author(s):  
A M Campbell
Keyword(s):  
Ionic Strength ◽  
Secondary Structure ◽  
Deoxyribonucleic Acid ◽  
Chromosome Structure ◽  
Tertiary Structure ◽  
Limiting Factors ◽  
Branch Points ◽  
Linear Dna ◽  
Dna Strands ◽  
Molecular Dimensions

The secondary structure of supercoiled DNA was varied by changes in ionic strength. For I = 0.075-0.4 the structure remained in the previously established branched form with only minor alterations in molecular dimensions. In 4M-NaCl, which induces linear DNA to change its secondary structure to the C structure and brings about an increase in the superhelix density of the molecule, no extra branches were observed on the molecules. The limiting factors that dictate supercoil structure seem to be the number and position of potential branch points and the proximity with which the two intertwining DNA strands can approach each other on the arms of the branches. This value is close to 10nm under the conditions described, and is 14-15nm at I = 0.2. It is suggested that such values should be borne in mind when models of chromosome structure are being constructed.

scholarly journals Deoxyribonucleic Acid Polymerase Associated with Avian Tumor Viruses: Secondary Structure of the Deoxyribonucleic Acid Product

1971 ◽  
Vol 7 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Lois Fanshier ◽  
Axel-Claude Garapin ◽  
Jerome McDonnell ◽  
Anthony Faras ◽  
Warren Levinson ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Deoxyribonucleic Acid ◽  
Acid Product ◽  
Tumor Viruses
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