Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1976-7-6
pubmed:abstractText
Two enzyme activities which release nucleotides preferentially from the 5' termini of DNA were found in T4-infected Escherichia coli. Since no corresponding activities were found in uninfected cells, the activities appeared to be induced by T4. Both activities are capable of excising pyrimidine dimers from ultraviolet-irradiated DNA which has been treated with T4 endonuclease V. One of the activities , referred to as T4 exonuclease B, was purified 400-fold from an extract of T4v 1- infected cells. The enzyme initiates hydrolysis of DNA specifically at the 5' termini to yield products which are mainly oligonucleotides of varying length. The hydrolysis reaction proceeds in a limited manner. The enzyme shows optimal activity at pH 7.0 and absolutely requires Mg2+. The molecular weight of the enzyme , as estimated by gel filtration, is approximately 35,000. Another activity, referred to as T4 exonuclease C, was purified 240-fold from the extract. This activity also excises pyrimidine dimers from ultraviolet-irradiated, incised DNA and releases nucleotides at 5' termini. It has a pH optimum at 7.5 and requires Mg2+. The molecular weight of the enzyme is approximately 20,000.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
251
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2613-9
pubmed:dateRevised
2000-12-18
pubmed:meshHeading
pubmed:year
1976
pubmed:articleTitle
5' leads to 3'-Exonucleases of bacteriophage T4.
pubmed:publicationType
Journal Article