Abstract
The excision of pyrimidine dimers from the deoxyribonucleic acid (DNA) of Neurospora crassa was examined. Postirradiation incubation in the presence of several chemicals known to inhibit various repair systems indicated that caffeine reduced the rate of excision twofold, but did not inhibit excision completely as did proflavine and quinacrine. Examination of the time course of excision showed that repair occurs at a relatively rapid rate: approximately 60 dimers excised per min after 500 ergs/mm2. Further evidence for rapid excision was obtained by sedimentation analysis of DNA; the maximal number of breaks introduced during repair was three, suggesting that breaks are repaired almost as fast as they are made and that only a few dimers are repaired at a time. Repair synthesis was measured by prelabeling the DNA with 15N and D2O, and then subjecting the DNA to equilibrium density gradient centrifugation after postirradiation incubation with 32P. Accumulation of single-strand breaks with increasing dose of ultraviolet radiation suggested that the limiting step was subsequent to the incision and excision steps of repair. Equilibrium CsCl centrifugation demonstrated that the limiting step in excision was repair synthesis.
Full text
PDF







Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Achey P., Billen D. Saturation of dark repair synthesis: accumulation of strand breaks. Biophys J. 1969 May;9(5):647–653. doi: 10.1016/S0006-3495(69)86409-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
- BOYCE R. P., HOWARD-FLANDERS P. RELEASE OF ULTRAVIOLET LIGHT-INDUCED THYMINE DIMERS FROM DNA IN E. COLI K-12. Proc Natl Acad Sci U S A. 1964 Feb;51:293–300. doi: 10.1073/pnas.51.2.293. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Billen D., Hewitt R. R., Lapthisophon T., Achey P. M. Deoxyribonucleic acid repair replication after ultraviolet light or x-ray exposure of bacteria. J Bacteriol. 1967 Nov;94(5):1538–1545. doi: 10.1128/jb.94.5.1538-1545.1967. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brunk C. F., Leick V. Rapid equilibrium isopycnic CsC1 gradients. Biochim Biophys Acta. 1969 Mar 18;179(1):136–144. doi: 10.1016/0005-2787(69)90129-4. [DOI] [PubMed] [Google Scholar]
- Carrier W. L., Setlow R. B. Paper strip method for assaying gradient fractions containing radioactive macromolecules. Anal Biochem. 1971 Oct;43(2):427–432. doi: 10.1016/0003-2697(71)90272-7. [DOI] [PubMed] [Google Scholar]
- Fuks Z., Smith K. C. Effect of quinacrine on x-ray sensitivity and the repair of damaged DNA in Escherichia coli K-12. Radiat Res. 1971 Oct;48(1):63–73. [PubMed] [Google Scholar]
- Grivell A. R., Jackson J. F. Thymidine kinase: evidence for its absence from Neurospora crassa and some other micro-organisms, and the relevance of this to the specific labelling of deoxyribonucleic acid. J Gen Microbiol. 1968 Dec;54(2):307–317. doi: 10.1099/00221287-54-2-307. [DOI] [PubMed] [Google Scholar]
- Haynes R. H. The interpretation of microbial inactivation and recovery phenomena. Radiat Res. 1966;(Suppl):1–29. [PubMed] [Google Scholar]
- Howard-Flanders P., Boyce R. P. DNA repair and genetic recombination: studies on mutants of Escherichia coli defective in these processes. Radiat Res. 1966;(Suppl):156+–156+. [PubMed] [Google Scholar]
- LINN S., LEHMAN I. R. AN ENDONUCLEASE FROM NEUROSPORA CRASSA SPECIFIC FOR POLYNUCLEOTIDES LACKING AN ORDERED STRUCTURE. I. PURIFICATION AND PROPERTIES OF THE ENZYME. J Biol Chem. 1965 Mar;240:1287–1293. [PubMed] [Google Scholar]
- Lawley P. D., Brookes P. Cytotoxicity of alkylating agents towards sensitive and resistant strains of Escherichia coli in relation to extent and mode of alkylation of cellular macromolecules and repair of alkylation lesions in deoxyribonucleic acids. Biochem J. 1968 Sep;109(3):433–447. doi: 10.1042/bj1090433. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lawley P. D., Brookes P. Molecular mechanism of the cytotoxic action of difunctional alkylating agents and of resistance to this action. Nature. 1965 May 1;206(983):480–483. doi: 10.1038/206480a0. [DOI] [PubMed] [Google Scholar]
- McGrath R. A., Williams R. W. Reconstruction in vivo of irradiated Escherichia coli deoxyribonucleic acid; the rejoining of broken pieces. Nature. 1966 Oct 29;212(5061):534–535. doi: 10.1038/212534a0. [DOI] [PubMed] [Google Scholar]
- PETTIJOHN D., HANAWALT P. EVIDENCE FOR REPAIR-REPLICATION OF ULTRAVIOLET DAMAGED DNA IN BACTERIA. J Mol Biol. 1964 Aug;9:395–410. doi: 10.1016/s0022-2836(64)80216-3. [DOI] [PubMed] [Google Scholar]
- Rauth A. M. Evidence for dark-reactivation of ultraviolet light damage in mouse L cells. Radiat Res. 1967 May;31(1):121–138. [PubMed] [Google Scholar]
- Regan J. D., Setlow R. B., Ley R. D. Normal and defective repair of damaged DNA in human cells: a sensitive assay utilizing the photolysis of bromodeoxyuridine. Proc Natl Acad Sci U S A. 1971 Apr;68(4):708–712. doi: 10.1073/pnas.68.4.708. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Regan J. D., Trosko J. E., Carrier W. L. Evidence for excision of ultraviolet-induced pyrimidine dimers from the DNA of human cells in vitro. Biophys J. 1968 Mar;8(3):319–325. doi: 10.1016/S0006-3495(68)86490-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SETLOW R. B., CARRIER W. L. THE DISAPPEARANCE OF THYMINE DIMERS FROM DNA: AN ERROR-CORRECTING MECHANISM. Proc Natl Acad Sci U S A. 1964 Feb;51:226–231. doi: 10.1073/pnas.51.2.226. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Setlow J. K., Randolph M. L., Boling M. E., Mattingly A., Price G., Gordon M. P. Repair of DNA in Haemophilus influenzae. II. Excision, repair of single-strand breaks, defects in transformation, and host cell modification in UV-sensitive mutants. Cold Spring Harb Symp Quant Biol. 1968;33:209–218. doi: 10.1101/sqb.1968.033.01.024. [DOI] [PubMed] [Google Scholar]
- Setlow R. B., Regan J. D., German J., Carrier W. L. Evidence that xeroderma pigmentosum cells do not perform the first step in the repair of ultraviolet damage to their DNA. Proc Natl Acad Sci U S A. 1969 Nov;64(3):1035–1041. doi: 10.1073/pnas.64.3.1035. [DOI] [PMC free article] [PubMed] [Google Scholar]
- WITKIN E. M. Modification of mutagenesis initiated by ultraviolet light through postteatment of bacteria with basic dyes. J Cell Comp Physiol. 1961 Dec;58(3):135–144. doi: 10.1002/jcp.1030580413. [DOI] [PubMed] [Google Scholar]
- Worthy T. E., Epler J. L. Repair of ultraviolet light-induced damage to the deoxyribonucleic acid of Neurospora crassa. J Bacteriol. 1972 Jun;110(3):1010–1016. doi: 10.1128/jb.110.3.1010-1016.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
