Sequence specificity of DNA repair by escherichia coli fpg protein

Robert Graves, Jacques Laval, Anthony E. Pegg

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

The sequence specificity of guanine methylation in DNA by N-methyl-N-nitrosourea and the subsequent repair of ringopened N7-methylguanine was studied using oligonucleotides of defined sequence. It was found that the methylation of TAGGGGCCCCTA was <2-fold greater than that occurring in TAGAGATCTCTA or TATGTGCACATA and 6-fold greater than in TACGCGCGCGTA. This is consistent with the concept that guanine methylation is least when the 5' preceding base is a pyrimidine and greatest when the 5' base is another guanine. These dodecamers were used to study repair by the Escherichia coli Fpg protein (formamidopyrimidine-DNA glycosylase) after the 7-methyl-guanine present in them was converted to the ring-opened form by alkaline treatment. The repair of ring-opened 7-methylguanine was much faster in self-complementary double-stranded 12mer substrates and was twice as rapid at 37°C in TAGGGGCCCTA campared with TACGCGCGCGTA. However, at 15°C, the relative rates were reversed since TACGCGCGCGTA was repaired at the same rate as at 37°C, whereas the repair of TAGGGGCCCCTA was much slower at 15°C. The repair of TAGGGGCCCCTA at 37°C was also much faster than the repair of TAGAGATCTCTA and was slightly more rapid than repair of TATGTGCACATA. Ligation of the dodecamer substrates to form 24mers or 36mers slightly reduced the initial rates of repair but did not abolish these differencs. These results indicate that under physicological conditions, the Fpg protetn is more active against adducts in guanine-rich regions and such regions may be the most likely sites of adduct formation at the N7-position of guanine which can then give rise to derivatives attacked by this enzyme.

Original languageEnglish (US)
Pages (from-to)1455-1459
Number of pages5
JournalCarcinogenesis
Volume13
Issue number8
DOIs
StatePublished - Aug 1 1992

Fingerprint

Escherichia coli Proteins
Guanine
DNA Repair
Methylation
DNA-Formamidopyrimidine Glycosylase
Methylnitrosourea
DNA Methylation
Oligonucleotides
Ligation
Enzymes

All Science Journal Classification (ASJC) codes

  • Cancer Research

Cite this

Graves, Robert ; Laval, Jacques ; Pegg, Anthony E. / Sequence specificity of DNA repair by escherichia coli fpg protein. In: Carcinogenesis. 1992 ; Vol. 13, No. 8. pp. 1455-1459.
@article{5806afd5d66e4291aec107f2c26d7b2e,
title = "Sequence specificity of DNA repair by escherichia coli fpg protein",
abstract = "The sequence specificity of guanine methylation in DNA by N-methyl-N-nitrosourea and the subsequent repair of ringopened N7-methylguanine was studied using oligonucleotides of defined sequence. It was found that the methylation of TAGGGGCCCCTA was <2-fold greater than that occurring in TAGAGATCTCTA or TATGTGCACATA and 6-fold greater than in TACGCGCGCGTA. This is consistent with the concept that guanine methylation is least when the 5' preceding base is a pyrimidine and greatest when the 5' base is another guanine. These dodecamers were used to study repair by the Escherichia coli Fpg protein (formamidopyrimidine-DNA glycosylase) after the 7-methyl-guanine present in them was converted to the ring-opened form by alkaline treatment. The repair of ring-opened 7-methylguanine was much faster in self-complementary double-stranded 12mer substrates and was twice as rapid at 37°C in TAGGGGCCCTA campared with TACGCGCGCGTA. However, at 15°C, the relative rates were reversed since TACGCGCGCGTA was repaired at the same rate as at 37°C, whereas the repair of TAGGGGCCCCTA was much slower at 15°C. The repair of TAGGGGCCCCTA at 37°C was also much faster than the repair of TAGAGATCTCTA and was slightly more rapid than repair of TATGTGCACATA. Ligation of the dodecamer substrates to form 24mers or 36mers slightly reduced the initial rates of repair but did not abolish these differencs. These results indicate that under physicological conditions, the Fpg protetn is more active against adducts in guanine-rich regions and such regions may be the most likely sites of adduct formation at the N7-position of guanine which can then give rise to derivatives attacked by this enzyme.",
author = "Robert Graves and Jacques Laval and Pegg, {Anthony E.}",
year = "1992",
month = "8",
day = "1",
doi = "10.1093/carcin/13.8.1455",
language = "English (US)",
volume = "13",
pages = "1455--1459",
journal = "Carcinogenesis",
issn = "0143-3334",
publisher = "Oxford University Press",
number = "8",

}

Sequence specificity of DNA repair by escherichia coli fpg protein. / Graves, Robert; Laval, Jacques; Pegg, Anthony E.

In: Carcinogenesis, Vol. 13, No. 8, 01.08.1992, p. 1455-1459.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Sequence specificity of DNA repair by escherichia coli fpg protein

AU - Graves, Robert

AU - Laval, Jacques

AU - Pegg, Anthony E.

PY - 1992/8/1

Y1 - 1992/8/1

N2 - The sequence specificity of guanine methylation in DNA by N-methyl-N-nitrosourea and the subsequent repair of ringopened N7-methylguanine was studied using oligonucleotides of defined sequence. It was found that the methylation of TAGGGGCCCCTA was <2-fold greater than that occurring in TAGAGATCTCTA or TATGTGCACATA and 6-fold greater than in TACGCGCGCGTA. This is consistent with the concept that guanine methylation is least when the 5' preceding base is a pyrimidine and greatest when the 5' base is another guanine. These dodecamers were used to study repair by the Escherichia coli Fpg protein (formamidopyrimidine-DNA glycosylase) after the 7-methyl-guanine present in them was converted to the ring-opened form by alkaline treatment. The repair of ring-opened 7-methylguanine was much faster in self-complementary double-stranded 12mer substrates and was twice as rapid at 37°C in TAGGGGCCCTA campared with TACGCGCGCGTA. However, at 15°C, the relative rates were reversed since TACGCGCGCGTA was repaired at the same rate as at 37°C, whereas the repair of TAGGGGCCCCTA was much slower at 15°C. The repair of TAGGGGCCCCTA at 37°C was also much faster than the repair of TAGAGATCTCTA and was slightly more rapid than repair of TATGTGCACATA. Ligation of the dodecamer substrates to form 24mers or 36mers slightly reduced the initial rates of repair but did not abolish these differencs. These results indicate that under physicological conditions, the Fpg protetn is more active against adducts in guanine-rich regions and such regions may be the most likely sites of adduct formation at the N7-position of guanine which can then give rise to derivatives attacked by this enzyme.

AB - The sequence specificity of guanine methylation in DNA by N-methyl-N-nitrosourea and the subsequent repair of ringopened N7-methylguanine was studied using oligonucleotides of defined sequence. It was found that the methylation of TAGGGGCCCCTA was <2-fold greater than that occurring in TAGAGATCTCTA or TATGTGCACATA and 6-fold greater than in TACGCGCGCGTA. This is consistent with the concept that guanine methylation is least when the 5' preceding base is a pyrimidine and greatest when the 5' base is another guanine. These dodecamers were used to study repair by the Escherichia coli Fpg protein (formamidopyrimidine-DNA glycosylase) after the 7-methyl-guanine present in them was converted to the ring-opened form by alkaline treatment. The repair of ring-opened 7-methylguanine was much faster in self-complementary double-stranded 12mer substrates and was twice as rapid at 37°C in TAGGGGCCCTA campared with TACGCGCGCGTA. However, at 15°C, the relative rates were reversed since TACGCGCGCGTA was repaired at the same rate as at 37°C, whereas the repair of TAGGGGCCCCTA was much slower at 15°C. The repair of TAGGGGCCCCTA at 37°C was also much faster than the repair of TAGAGATCTCTA and was slightly more rapid than repair of TATGTGCACATA. Ligation of the dodecamer substrates to form 24mers or 36mers slightly reduced the initial rates of repair but did not abolish these differencs. These results indicate that under physicological conditions, the Fpg protetn is more active against adducts in guanine-rich regions and such regions may be the most likely sites of adduct formation at the N7-position of guanine which can then give rise to derivatives attacked by this enzyme.

UR - http://www.scopus.com/inward/record.url?scp=0026787240&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026787240&partnerID=8YFLogxK

U2 - 10.1093/carcin/13.8.1455

DO - 10.1093/carcin/13.8.1455

M3 - Article

C2 - 1499097

AN - SCOPUS:0026787240

VL - 13

SP - 1455

EP - 1459

JO - Carcinogenesis

JF - Carcinogenesis

SN - 0143-3334

IS - 8

ER -