Repair defect mutants of Proteus mirabilis. II. Excision of pyrimidine dimers from the DNA of ultraviolet-irradiated P. mirabilis wild-type and uv-sensitive mutants

Journal Article · Mon Jan 01 04:00:00 EST 1973 · Mol. Gen. Genet., v. 124, no. 3, pp. 259-268

OSTI ID:4424306

Stoerl, K; Mund, C; Venner, H

Two photoproducts, thymine-thymine and cytosine-thymine dimers were identified after uv irradiation of Proteus mirabilis. It was found that 1 erg/mm/ sup 2/ at 253 nm produced approximately 2.9 x 10/sup -6/ pyrimidine dimers/ thymine residues or about 8 dimers per 10/sup 7/ nucleotides. Both photoproducts were excised at the same rate from the DNA of ultraviolet-resistant wild-type cells (PG 273, PG 758), but remained in acid precipitable DNA in ultravioletsensitive HCR-mutants (PG 678, PG 686). The excised dimers appeared both in the TCA-soluble cell fraction and in the medium outside the cells. EXR- mutants (PG 693, PG 699) also demonstrated excision capability. The excision ability of the REC-mutant (PG 672) could not be unambiguously demonstrated, because of high DNA-degradation. The number of excised dimers depended on the uv dose. In contrast to HCR-mutants of Escherichia coli, HCR-mutants of P. mirabilis showed DNA-degradation at about the same rate as the wild-type strain during repair after uv irradiation. (auth)

• Research Organization: Deutsche Akademie der Wissenschaften, Berlin
• NSA Number: NSA-29-000519
• OSTI ID: 4424306
• Journal Information: Mol. Gen. Genet., v. 124, no. 3, pp. 259-268, Journal Name: Mol. Gen. Genet., v. 124, no. 3, pp. 259-268; ISSN MGGEA
• Country of Publication: Germany
• Language: English

Related Subjects

*DNA-- STRAND BREAKS
*PYRIMIDINES-- CHEMICAL RADIATION EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL REPAIR
DIMERS
DOSE-RESPONSE RELATIONSHIPS
HOST-CELL REACTIVATION
IRRADIATION
MUTANTS
N48120* --Life Sciences--Radiation Effects on Biochemicals-- In Microorganisms
N48310 --Life Sciences--Radiation Effects on Microorganisms--Basic Studies
PHOTON BEAMS
PROTEINS
RADIOBIOLOGY
RADIOSENSITIVITY
ULTRAVIOLET RADIATION