Completion of excision repair patches in human cell preparations: identification of a probable mode of excision and resynthesis

Journal Article · Thu Mar 01 04:00:00 EST 1984 · Carcinogenesis (N.Y.); (United States)

DOI:https://doi.org/10.1093/carcin/5.3.325· OSTI ID:7005402

Cleaver, J E

Excision repair of u.v. damage in human fibroblasts is more sensitive to inhibitors of DNA polymerase alpha (cytosine arabinoside, aphidicolin) than to an inhibitor of polymerase beta (dideoxythymidine), which indicates a greater role in repair for polymerase alpha than for polymerase beta. These inhibitors all generate shortened patches with free 3' termini; the detailed structure of these patches was investigated in permeable cells or isolated nuclei by degradation of DNA with exonuclease III and by resynthesis with DNA polymerase I (Klenow fragment) and T4 DNA ligase. The structure of the shortened patches appears to be a short stretch of DNA synthesized in the 5'----3' direction within a longer single-strand gap. The single-strand gap ahead of the 3' terminus can be bridged only by the combined action of polymerase and ligase. This structure implies that excision must involve removal of an oligonucleotide or widening of a gap by 5'----3' exonuclease action to produce a single-strand region wide enough to be a substrate for polymerase alpha. There is no evidence for structures generated by nick translation or strand displacement.

• Research Organization: Laboratory of Radiobiology and Environmental Health, University of California, San Francisco
• OSTI ID: 7005402
• Journal Information: Carcinogenesis (N.Y.); (United States), Journal Name: Carcinogenesis (N.Y.); (United States) Vol. 5:3; ISSN CRNGD
• Country of Publication: United States
• Language: English

Related Subjects

560111* -- Radiation Effects on Biochemicals-- In Vitro-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CONNECTIVE TISSUE CELLS
DNA
DNA POLYMERASES
ELECTROMAGNETIC RADIATION
ENZYME INHIBITORS
ENZYMES
FIBROBLASTS
NUCLEIC ACIDS
NUCLEOTIDYLTRANSFERASES
ORGANIC COMPOUNDS
PHOSPHORUS-GROUP TRANSFERASES
POLYMERASES
RADIATIONS
RECOVERY
REPAIR
SENSITIVITY
SOMATIC CELLS
TRANSFERASES
ULTRAVIOLET RADIATION