Open AccessSelective Elimination of the Exonuclease Activity of the Deoxyribonucleic Acid Polymerase from Escherichia coli B by Limited Proteolysis
Author(s) -
Hans Klenow,
I. Henningsen
Publication year - 1970
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.65.1.168
Subject(s) - enzyme , exonuclease , dna polymerase i , subtilisin , polymerase , biochemistry , enzyme assay , proteolysis , dna polymerase , microbiology and biotechnology , chemistry , escherichia coli , size exclusion chromatography , biology , polymerase chain reaction , reverse transcriptase , gene
Purification of DNA polymerase fromE. coli B has in two cases each time led to the isolation of two separate polymerase activities, enzyme A and enzyme B. Enzyme A was in contrast to enzyme B almost completely devoid of exonuclease activity. Each of the two enzymes yielded a single symmetrical activity peak in gel filtration chromatograms. From the elution volumes the molecular weights were estimated to be about 70,000 for enzyme A and about 150,000 for enzyme B.Treatment of enzyme B with subtilisin led to an increase of about 30 per cent of the polymerase activity while the exonuclease activity almost completely disappeared. The product of the subtilisin treatment (enzyme C) gave rise to a single symmetrical polymerase activity peak in a gel filtration chromatogram. The elution volume was identical to that obtained with enzyme A. It is concluded that enzyme A and enzyme C are formed by limited proteolysis of enzyme B.