DNA turnover and strand breaks in Escherichia coli

Conference · Wed Jan 01 04:00:00 EST 1975

OSTI ID:4119369

Hanawalt, P; Grivell, A; Nakayama, H; Hanawalt, P C ^[1]

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1. ed.

The extent of DNA turnover has been measured in a dnaB mutant of Escherichia coli, temperature sensitive for semiconservative DNA replication. At the nonpermissive temperature about 0.02 percent of the deoxynucleotides in DNA are exchanged per generation period. This turnover rate is markedly depressed in the presence of rifampicin. During thymine starvation strand breaks accumulate in the DNA of E. coli strains that are susceptible to thymineless death. Rifampicin suppresses the appearance of these breaks, consistent with our hypothesis that transcription may be accompanied by repairable single-strand breaks in DNA. DNA turnover is enhanced severalfold in strands containing 5- bromodeoxyuridine in place of thymidine, possibly because the analog (or the deoxyuridine, following debromination) is sometimes recognized and excised. (auth)

• Research Organization: Stanford Univ., CA
• NSA Number: NSA-33-012522
• OSTI ID: 4119369
• Country of Publication: United States
• Language: English

Related Subjects

*BUDR-- BIOLOGICAL EFFECTS
*DNA-- STRAND BREAKS
*ESCHERICHIA COLI
550201* --Biomedical Sciences
Basic Studies--Biochemistry-- Tracer Techniques
MUTANTS
N48830* --Life Sciences--New Tracer Techniques--Other
NUCLEOTIDES
THYMIDINE