In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 94, No. 11 ( 1997-05-27), p. 5733-5738
Kurzfassung:
Mutations are permanent DNA sequence changes that can be induced when replication occurs on a damaged DNA template. In Escherichia coli , the process of translesion synthesis past a lesion that hinders replication requires the induction of SOS-controlled gene products, among which are those of the umuDC operon. To study translesion synthesis in vivo , we have constructed single-stranded vectors containing single 2-acetylaminofluorene adducts located within −1 and −2 frameshift mutation hot spots formed by short repetitive sequences. These adducts strongly hinder DNA replication as only 2–5% of the molecules give rise to progeny under non-SOS-induced conditions. Induction of the SOS response lead to a 10-fold increase in survival. Adducts present within repetitive sequences trigger the formation of misaligned primer/template replication intermediates which, upon elongation, will result in the fixation of frameshift errors (mutagenic translesion synthesis). Surprisingly we find that elongation from the nonslipped intermediate depends upon functional umuDC + gene products, whereas elongation from the slipped intermediate is umuDC + independent but requires another, as yet biochemically uncharacterized, SOS function. These data are discussed in terms of the different steps involved during translesion synthesis through a replication-blocking lesion.
Materialart:
Online-Ressource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.94.11.5733
Sprache:
Englisch
Verlag:
Proceedings of the National Academy of Sciences
Publikationsdatum:
1997
ZDB Id:
209104-5
ZDB Id:
1461794-8
SSG:
11
SSG:
12
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