Naslov
ExoI, ExoVII and SbcCD nucleases participate in "reckless" DNA degradation in Escherichia coli

Autori
Zahradka, Ksenija ; Repar, Jelena ; Buljubašić, Maja ; Zahradka, Davor

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
BioMicroWorld 2013 - Book of Abstracts / - , 2013, 534-534

Skup
BioMicroWorld 2013 - V International Conference on Environmental, Industrial and Applied Microbiology

Mjesto i datum
Madrid, Španjolska, 02.10.2013. - 04.10.2013

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Escherichia coli; recA mutants; reckless DNA degradation; RecBCD; ExoI; ExoVII; SbcCD; UV irradiation

Sažetak
The recA mutants of Escherichia coli display pronounced DNA degradation that starts at sites of double-strand DNA breaks (DSBs), and is mediated by RecBCD exonuclease (ExoV). As a consequence of this "reckless" DNA degradation, populations of recA mutants contain a large proportion of anucleate cells. We have found that the xonA and sbcD mutations, which inactivate exonuclease I (ExoI) and SbcCD nuclease, respectively, markedly suppress "reckless" DNA degradation [1]. The suppressive effect of these mutations was observed in normally grown, as well as in UV-irradiated, recA cells. In addition, we have shown that inactivation of ExoVII by a xseA mutation contributes to attenuation of DNA degradation in UV-irradiated recA mutants [2]. The xseA mutation itself has only a weak effect, however, it acts synergistically with the xonA or sbcD mutations in suppressing "reckless" degradation. The quadruple xseA xonA sbcD recA mutants show no sign of DNA degradation during postirradiation incubation, suggesting that ExoVII, together with ExoI and SbcCD, plays a crucial role in regulating RecBCD-catalyzed chromosome degradation. We propose that these nucleases act on DSBs to create blunt DNA ends, the preferred substrates for RecBCD binding.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA