TY - JOUR
T1 - Mutator strains of Escherichia coli, mutD and dnaQ, with defective exonucleolytic editing by DNA polymerase III holoenzyme
AU - Echols, H.
AU - Lu, C.
AU - Burgers, P. M.J.
PY - 1983
Y1 - 1983
N2 - The closely linked mutD and dnaQ mutations confer a vastly increased mutation rate on Escherichia coli and thus might define a gene with a central role in the fidelity of DNA replication. To look for the biochemical function of the mutD gene product, we have measured the 3'→5' exonucleolytic editing activity of polymerase III holoenzyme from mutD5 and dnaQ49 mutants. The editing activities of the mutant enzymes are defective compared to wild type, as judged by two assays: (i) decreased excision of a terminal mispaired base from a copolymer substrate and (ii) turnover of dTTP to dTMP during replication with a phage G4 DNA template. Thus, the mutD (dnaQ) gene product is likely to control the editing (proofreading) capacity of polymerase III holoenzyme.
AB - The closely linked mutD and dnaQ mutations confer a vastly increased mutation rate on Escherichia coli and thus might define a gene with a central role in the fidelity of DNA replication. To look for the biochemical function of the mutD gene product, we have measured the 3'→5' exonucleolytic editing activity of polymerase III holoenzyme from mutD5 and dnaQ49 mutants. The editing activities of the mutant enzymes are defective compared to wild type, as judged by two assays: (i) decreased excision of a terminal mispaired base from a copolymer substrate and (ii) turnover of dTTP to dTMP during replication with a phage G4 DNA template. Thus, the mutD (dnaQ) gene product is likely to control the editing (proofreading) capacity of polymerase III holoenzyme.
UR - http://www.scopus.com/inward/record.url?scp=0242556207&partnerID=8YFLogxK
U2 - 10.1073/pnas.80.8.2189
DO - 10.1073/pnas.80.8.2189
M3 - Article
C2 - 6340117
AN - SCOPUS:0242556207
VL - 80
SP - 2189
EP - 2192
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 8 I
ER -