Fragmentation of replicating chromosomes triggered by uracil in DNA

被引:53
作者
Kouzminova, EA [1 ]
Kuzminov, A [1 ]
机构
[1] Univ Illinois, Dept Microbiol, Urbana, IL 61801 USA
关键词
dut; uracil; recBC; double-strand breaks; chromosomal fragmentation;
D O I
10.1016/j.jmb.2005.10.044
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The dut mutants of Escherichia coli fail to hydrolyze dUTP and thus incorporate uracil into their DNA, suffering from chromosomal fragmentation. The postulated mechanism for the double-strand DNA breaks is clustered uracil excision, which requires high density of DNA-uracils. However, we did not find enough uracil residues or excision nicks in the DNA of dut mutants to account for clustered uracil excision. Using a dut recBC(Ts) mutant of E. coli to inquire into the mechanism of uracil-triggered chromosomal fragmentation, we show that this fragmentation requires DNA replication and, in turn, inhibits replication of the chromosomal terminus. As a result, origin-containing sub-chromosomal fragments accumulate in dut recBC conditions, indicating preferential demise of replication bubbles. We propose that the basic mechanism of the uracil-triggered chromosomal fragmentation is replication fork collapse at uracil-excision nicks. Possible explanations for the low level terminus fragmentation are also considered.
引用
收藏
页码:20 / 33
页数:14
相关论文
共 54 条
[1]   Thymine metabolism and thymineless death in prokaryotes and eukaryotes [J].
Ahmad, SI ;
Kirk, SH ;
Eisenstark, A .
ANNUAL REVIEW OF MICROBIOLOGY, 1998, 52 :591-625
[2]   ENZYMATIC SYNTHESIS OF DEOXYRIBONUCLEIC ACID .3. THE INCORPORATION OF PYRIMIDINE AND PURINE ANALOGUES INTO DEOXYRIBONUCLEIC ACID [J].
BESSMAN, MJ ;
LEHMAN, IR ;
ADLER, J ;
ZIMMERMAN, SB ;
SIMMS, ES ;
KORNBERG, A .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1958, 44 (07) :633-640
[3]   REGULATION OF PYRIMIDINE DEOXYRIBONUCLEOTIDE METABOLISM BY SUBSTRATE CYCLES IN DCMP DEAMINASE-DEFICIENT V79 HAMSTER-CELLS [J].
BIANCHI, V ;
PONTIS, E ;
REICHARD, P .
MOLECULAR AND CELLULAR BIOLOGY, 1987, 7 (12) :4218-4224
[4]   Replication fork collapse at replication terminator sequences [J].
Bidnenko, V ;
Ehrlich, SD ;
Michel, B .
EMBO JOURNAL, 2002, 21 (14) :3898-3907
[6]  
BIRNBOIM HC, 1983, METHOD ENZYMOL, V100, P243
[7]   Abortive base-excision repair of radiation-induced clustered DNA lesions in Escherichia coli [J].
Blaisdell, JO ;
Wallace, SS .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2001, 98 (13) :7426-7430
[8]   Folate deficiency causes uracil misincorporation into human DNA and chromosome breakage: Implications for cancer and neuronal damage [J].
Blount, BC ;
Mack, MM ;
Wehr, CM ;
MacGregor, JT ;
Hiatt, RA ;
Wang, G ;
Wickramasinghe, SN ;
Everson, RB ;
Ames, BN .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1997, 94 (07) :3290-3295
[9]   ENZYMATIC PRODUCTION OF DEOXYRIBONUCLEIC-ACID DOUBLE-STRAND BREAKS AFTER ULTRAVIOLET-IRRADIATION OF ESCHERICHIA-COLI K-12 [J].
BONURA, T ;
SMITH, KC .
JOURNAL OF BACTERIOLOGY, 1975, 121 (02) :511-517
[10]   RdgB acts to avoid chromosome fragmentation in Escherichia coli [J].
Bradshaw, JS ;
Kuzminov, A .
MOLECULAR MICROBIOLOGY, 2003, 48 (06) :1711-1725