TY - JOUR
T1 - Patterns of chromosomal fragmentation due to uracil-DNA incorporation reveal a novel mechanism of replication-dependent double-stranded breaks
AU - Kouzminova, Elena A.
AU - Kuzminov, Andrei
PY - 2008/4
Y1 - 2008/4
N2 - There is growing evidence that spontaneous chromosomal fragmentation, one of the main contributors to genetic instability, is intimately linked to DNA replication. In particular, we proposed before that uracil incorporation in DNA triggers chromosomal fragmentation due to replication fork collapse at uracil-excision intermediates. We tested predictions of this model at the chromosomal level in the dut mutants of Escherichia coli, by determining the relationship between DNA replication and patterns of fragmentation in defined chromosomal segments. Here we show that the uracil-DNA-triggered chromosomal fragmentation: (i) has a gradient that parallels the replication gradient, (ii) shows polarity within defined segments pointing towards replication origins and (iii) reorganizes to match induced replication gradients, confirming its dynamic pattern. Unexpectedly, these fragmentation patterns not only support the replication fork collapse model, but also reveal another mechanism of the replication-dependent chromosomal fragmentation triggered by uracil excision.
AB - There is growing evidence that spontaneous chromosomal fragmentation, one of the main contributors to genetic instability, is intimately linked to DNA replication. In particular, we proposed before that uracil incorporation in DNA triggers chromosomal fragmentation due to replication fork collapse at uracil-excision intermediates. We tested predictions of this model at the chromosomal level in the dut mutants of Escherichia coli, by determining the relationship between DNA replication and patterns of fragmentation in defined chromosomal segments. Here we show that the uracil-DNA-triggered chromosomal fragmentation: (i) has a gradient that parallels the replication gradient, (ii) shows polarity within defined segments pointing towards replication origins and (iii) reorganizes to match induced replication gradients, confirming its dynamic pattern. Unexpectedly, these fragmentation patterns not only support the replication fork collapse model, but also reveal another mechanism of the replication-dependent chromosomal fragmentation triggered by uracil excision.
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U2 - 10.1111/j.1365-2958.2008.06149.x
DO - 10.1111/j.1365-2958.2008.06149.x
M3 - Article
C2 - 18312272
AN - SCOPUS:40549129679
SN - 0950-382X
VL - 68
SP - 202
EP - 215
JO - Molecular Microbiology
JF - Molecular Microbiology
IS - 1
ER -