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Titolo:
MUTATION SPECTRA OF M13 VECTORS CONTAINING SITE-SPECIFIC CIS-SYN, TRANS-SYN-I, (6-4), AND DEWAR PYRIMIDONE PHOTOPRODUCTS OF THYMIDYLYL-(3'-]5')-THYMIDINE IN ESCHERICHIA-COLI UNDER SOS CONDITIONS
Autore:
SMITH CA; WANG M; JIANG N; CHE L; ZHAO XD; TAYLOR JS;
Indirizzi:
WASHINGTON UNIV,DEPT CHEM ST LOUIS MO 63130 WASHINGTON UNIV,DEPT CHEM ST LOUIS MO 63130
Titolo Testata:
Biochemistry
fascicolo: 13, volume: 35, anno: 1996,
pagine: 4146 - 4154
SICI:
0006-2960(1996)35:13<4146:MSOMVC>2.0.ZU;2-9
Fonte:
ISI
Lingua:
ENG
Soggetto:
T CYCLOBUTANE DIMERS; PHENOTYPIC SELECTION; ULTRAVIOLET-LIGHT; UV MUTAGENESIS; DNA PHOTOLYASE; THYMINE DIMER; REPAIR; PHOTOCHEMISTRY; FREQUENCY; PRODUCTS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
41
Recensione:
Indirizzi per estratti:
Citazione:
C.A. Smith et al., "MUTATION SPECTRA OF M13 VECTORS CONTAINING SITE-SPECIFIC CIS-SYN, TRANS-SYN-I, (6-4), AND DEWAR PYRIMIDONE PHOTOPRODUCTS OF THYMIDYLYL-(3'-]5')-THYMIDINE IN ESCHERICHIA-COLI UNDER SOS CONDITIONS", Biochemistry, 35(13), 1996, pp. 4146-4154

Abstract

The mutation spectra of cis-syn, trans-syn-I, (6-4), and Dewar pyrimidone photoproducts of the TT site of AATTAA and TATTAT in the (-) strand of a heteroduplex M13 vector were obtained in an excision and photoreversal repair deficient Escherichia coli host under SOS conditions. Oligonucleotides containing site-specific photoproducts were annealed to a complementary uracil-containing (+) strand that contained one or more unique pairs of nucleotide mismatches and used to prime (-) strand synthesis with a DNA polymerase and dNTPs. Following DNA synthesis, the reaction mixtures were incubated with T4 DNA ligase and ATP and then used to transfect SOS-induced competent CSRO6F' cells (uvrA6 and phr-1). The transfectants were plated, gridded, and probed by oligonucleotides specific for progeny of the (-) and (+) strands. Individual progeny of the photoproduct-containing (-) strands were plaque purified and sequenced by the dideoxy method. The cis-syn and trans-syn-I dimerswere found not to be very mutagenic (<9%), the Dewar product more so (<33%), and the (6-4) product the most mutagenic (<73%). The mutation spectra were similar to those previously reported for the same photoproducts of the TT site of AGTTGG in the (+) strand of an M13 vector [Lawrence, C. W., et al. (1990) Mel. Gen. Genet. 222, 166-168; LeClerc, J. E., et al. (1991) Proc. Natl. Acad., Sci. U.S,A, 88, 9685-9689] except that -1 deletion mutations were not observed for the trans-syn-I photoproducts, and a lower frequency of 3'-T-->C mutations was observed for the (6-4) photoproduct. Evidence that a small percentage of (+) strand repair of a double mismatch to the 3'-side of the photoproduct site was obtained from transfection experiments in which a second doublemismatch was introduced opposite or flanking the photoproduct. Analysis of the minor tandem mutations induced by the (6-4) and Dewar products suggests that the SOS polymerase complex is able to elongate what amounts to double mismatches opposite these photoproducts and is consistent with the action of a highly processive polymerase that lacks proofreading ability.

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Documento generato il 18/02/20 alle ore 14:04:04