Linked Life Data

6696910

Source:http://linkedlifedata.com/resource/pubmed/id/6696910

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1984-4-11
pubmed:abstractText
We have isolated a closed circular duplex DNA fraction from the unicellular parasite Isospora (Toxoplasma) gondii and examined the purified DNA by electron microscopy. A major part of this circular DNA consists of 12-micron circles containing a cruciform with 0.5-micron tails. We also found 23-micron circles with the properties expected of head-to-tail dimers of the 12-micron circles. Some of these dimers have two cruciforms with 0.4-micron tails, some have one cruciform with 0.8-micron tails. When ethidium bromide was diffused into the DNA solution, circles with tails were replaced by twisted circles without tails. Direct mixing of the DNA with high ethidium bromide concentrations (5 micrograms/ml) gave rise to highly twisted circles with tails. This proves that the tailed circles are covalently continuous and indicates that ethidium bromide blocks branch migration. The 0.5-micron tails are part of a 1.7-micron palindrome, which was visualized by spreading denatured DNA under snap-back conditions. We argue that the cruciform is not present in vivo and that the 12-micron circles may represent the mitochondrial DNA of Toxoplasma.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
24
pubmed:volume
781
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
100-11
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
DNA circles with cruciforms from Isospora (Toxoplasma) gondii.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't