Identification, purification, and characterization of Escherichia coli virus T1 DNA methyltransferase.
J Biol Chem
; 262(31): 15225-31, 1987 Nov 05.
Article
in En
| MEDLINE
| ID: mdl-3312202
ABSTRACT
An Escherichia coli virus T1-induced DNA methyltransferase was identified by activity gel analysis in homogenates of infected E. coli DNA-adenine-methylation-deficient strains. Although the Mr of this protein (31,000) is in the same range as that of the E. coli DNA adenine methyltransferase, the two proteins are not closely related; the E. coli dam gene does not hybridize with T1 DNA. Selective conditions for measurement of the T1 activity were developed, and the enzyme was purified to functional homogeneity, as shown by activity analysis in polyacrylamide gels. Requirements for optimal activity of the viral enzyme were determined to be pH 6.9, ionic strengths below 0.1 M KCl, and a temperature between 40 and 43 degrees C. The Km for S-adenosyl-L-methionine is 4.9 microM. The purified T1 DNA methyltransferase is capable of methylating adenine in 5'-GATC-3' sites in vitro.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
T-Phages
/
DNA (Cytosine-5-)-Methyltransferases
/
Escherichia coli
Type of study:
Diagnostic_studies
Language:
En
Journal:
J Biol Chem
Year:
1987
Document type:
Article
Affiliation country:
Austria
Publication country:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
/
US
/
USA