Linked Life Data

7926842

Source:http://linkedlifedata.com/resource/pubmed/id/7926842

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1994-11-18
pubmed:abstractText
To study the effects of in vivo DNA methylation, we have developed an inducible system to control the intracellular concentration of S-adenosyl-L-methionine (AdoMet). The product of the bacteriophage T3 AdoMet hydrolase-encoding gene (amh), which degrades AdoMet to L-homoserine and 5'-methylthioadenosine, was employed to lower AdoMet concentrations in vivo. The amh gene was placed downstream from the inducible tetA promoter of the Tn10 tetracycline regulon substituting for most of the tetA gene. Unlike in the original isolates [Hughes et al., J. Bacteriol. 169 (1987) 3625-2632], this promoter allows controlled expression. These constructs are stable and can be induced in a dose-dependent manner. The system is maximally induced 2-3 h after addition of the inducer, autoclaved chlortetracycline (cTc). DNA methylation in vivo was assessed in this model system by BamHI cleavage of plasmid DNA isolated from cells cotransformed by two compatible plasmids, one carrying the inducible amh gene, the other M.BamHII methyltransferase encoding gene. The induction of amh decreased the intracellular pool of AdoMet which M.BamHII requires as a cofactor. Under these conditions, there is a decrease in DNA methylation. The unmethylated DNA is assayed by BamHI cleavage. This system will be useful for studying transcription, DNA replication, gene repair and other cellular phenomena affected by methylation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0378-1119
pubmed:author
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
148
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
75-80
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
A novel Tn10 tetracycline regulon system controlling expression of the bacteriophage T3 gene encoding S-adenosyl-L-methionine hydrolase.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, Georgetown University, Washington, DC 20007.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't