TY - JOUR
T1 - Excision of thymine dimers by proteolytic and amber fragments of E. coli DNA polymerase I
AU - Friedberg, Errol C.
AU - Lehman, I. R.
N1 - Funding Information:
We thank Janice Chien and Karin Goldmann assistance. This work was supported by grants (GM-06196 to IRL) from the USPHS, and contract U.S. Atomic Energy Commission (to ECF). E.C.F. Andrew W. Mellon Foundation.
PY - 1974/5/7
Y1 - 1974/5/7
N2 - Excision of thymine dimers from specifically incised ultraviolet irradiated DNA by E. coli DNA polymerase I is stimulated by concurrent DNA synthesis. The 36,000 molecular-weight "small fragment" obtained by limited proteolysis of DNA polymerase I, which retains only the 5′ → 3′ exonuclease activity, also excises thymine dimers, but at one-tenth the rate of the intact enzyme. However, the rate of excision is increased by addition of the "large" 76,000-molecular weight fragment. With the further addition of the 4 deoxynucleoside triphosphates, permitting DNA synthesis to occur, excision approaches rates observed with the intact enzyme. The same result was obtained with a fragment of DNA polymerase I with 5′ → 3′ exonuclease activity that is present uniquely in polymerase I amber mutants.
AB - Excision of thymine dimers from specifically incised ultraviolet irradiated DNA by E. coli DNA polymerase I is stimulated by concurrent DNA synthesis. The 36,000 molecular-weight "small fragment" obtained by limited proteolysis of DNA polymerase I, which retains only the 5′ → 3′ exonuclease activity, also excises thymine dimers, but at one-tenth the rate of the intact enzyme. However, the rate of excision is increased by addition of the "large" 76,000-molecular weight fragment. With the further addition of the 4 deoxynucleoside triphosphates, permitting DNA synthesis to occur, excision approaches rates observed with the intact enzyme. The same result was obtained with a fragment of DNA polymerase I with 5′ → 3′ exonuclease activity that is present uniquely in polymerase I amber mutants.
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U2 - 10.1016/0006-291X(74)90901-2
DO - 10.1016/0006-291X(74)90901-2
M3 - Article
C2 - 4598440
AN - SCOPUS:0016234086
SN - 0006-291X
VL - 58
SP - 132
EP - 139
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 1
ER -