DNA Polymerase Required for Rapid Repair of X-ray—Induced DNA Strand Breaks in vivo

Science  21 May 1971:
Vol. 172, Issue 3985, pp. 851-854
DOI: 10.1126/science.172.3985.851


A much higher yield of DNA single-strand breaks was obtained in the DNA polymerase-deficient mutant Escherichia coli K-12 pol A1 after a given dose of x-rays than had been found before in Escherichia coli. The increased yield of single-strand breaks was due to the absence of a rapid repair system, which had not been described in Escherichia coli K-12. This absence probably accounts for the x-ray sensitivity of the pol A1 mutant. The rapid repair system can be reversibly inhibited in pol+ cells.