Substrate overlap and functional competition between human nucleotide excision repair and Escherichia coli photolyase and (A)BC excision nuclease

Journal Article · Tue Jun 19 00:00:00 EDT 1990 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00476a011· OSTI ID:6288674

Sibghat-Ullah,; Sancar, Z ^[1]

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1. Univ. of North Carolina School of Medicine, Chapel Hill (USA)

Human cell free extract prepared by the method of Manley et al. carries out repair synthesis on UV-irradiated DNA. Removal of pyrimidine dimers by photoreactivation with DNA photolyase reduces repair synthesis by about 50%. With excess enzyme in the reaction mixture photolyase reduced the repair signal by the same amount even in the absence of photoreactivating light, presumably by binding to pyrimidine dimers and interfering with the binding of human damage recognition protein. Similarly, the UvrB subunit of Escherichia coli (A)BC excinuclease when loaded onto UV-irradiated or psoralen-adducted DNA inhibited repair synthesis by cell-free extract by 75-80%. The opposite was true also as HeLa cell free extract specifically inhibited the photorepair of a thymine dimer by DNA photolyase and its removal by (A)BC excinuclease. Cell-free extracts from xeroderma pigmentosum (XP) complementation groups A and C were equally effective in blocking the E. coli repair proteins, while extracts from complementation groups D and E were ineffective in blocking the E. coli enzyme. These results suggest that XP-D and XP-E cells are defective in the damage recognition subunits(s) of human excision nuclease.

• OSTI ID: 6288674
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 29:24; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

560120* -- Radiation Effects on Biochemicals
Cells
& Tissue Culture
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANTICOAGULANTS
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
BODY
COUMARINS
DISEASES
DNA
DNA REPAIR
DRUGS
ELECTROMAGNETIC RADIATION
ENZYMES
ESCHERICHIA COLI
ESTERASES
EXCISION REPAIR
EXTREME ULTRAVIOLET RADIATION
HELA CELLS
HEMATOLOGIC AGENTS
HETEROCYCLIC COMPOUNDS
HYDROLASES
INHIBITION
MICROORGANISMS
NUCLEASES
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANS
PHOSPHODIESTERASES
PSORALEN
PYRIMIDINE DIMERS
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
SKIN
SKIN DISEASES
ULTRAVIOLET RADIATION
XERODERMA PIGMENTOSUM
XP CELLS