Bacteriophage N4-coded 5'----3' exonuclease. Purification and characterization.
نویسندگان
چکیده
منابع مشابه
Construction and characterization of a bacteriophage T4 DNA polymerase deficient in 3'-->5' exonuclease activity.
Bacteriophage T4 DNA polymerase has a proofreading 3'-->5' exonuclease that plays an important role in maintaining the accuracy of DNA replication. We have constructed a T4 DNA polymerase deficient in this exonuclease by converting Asp-219 to Ala. The exonuclease activity of the mutant T4 DNA polymerase has been reduced by a factor of at least 10(7), but it retains a polymerase activity whose k...
متن کاملPurification and characterization of the coliphage N4-coded single-stranded DNA binding protein.
We have purified and characterized a single-stranded DNA binding protein (N4 SSB) induced after coliphage N4 infection. It has a monomeric molecular weight of 31,000 and contains 10 tyrosine and 1-2 tryptophan amino acid residues. Its fluorescence spectrum is dominated by the tyrosine residues, and their fluorescence is quenched when the protein binds single-stranded DNA. Fluorescence quenching...
متن کاملDouble-strand break repair in bacteriophage T4: recombination effects of 3'-5' exonuclease mutations.
The role of 3'-5' exonucleases in double-strand break (DSB)-promoted recombination was studied in crosses of bacteriophage T4, in which DSBs were induced site specifically within the rIIB gene by SegC endonuclease in the DNA of only one of the parents. Frequency of rII+ recombinants was measured in two-factor crosses of the type i x ets1, where ets1 designates an insertion in the rIIB gene carr...
متن کاملPurification and characterization of a mammalian endo-exonuclease.
An endo-exonuclease has been purified from cultured monkey (CV-1) cells. The enzyme which was purified to near homogeneity to be a 65 kDa monomeric protein. The single-strand DNase activity is endonucleolytic and nonprocessive, whereas the double-strand DNase activity is exonucleolytic and processive. The enzyme was also found to have RNase activity using poly-rA as substrate. The pH optimum fo...
متن کامل5 ’ + 3 ’ - Exonucleases of Bacteriophage
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 appear 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 activi...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1986
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(18)67447-2