recD sbcB sbcD mutants are deficient in recombinational repair of UV lesions by RecBC.
نویسندگان
چکیده
In recD sbcB sbcD mutants, repair of UV-irradiated DNA is strongly RecF dependent, indicating that RecBC is inactive. This finding suggests that exonuclease V, exonuclease I (SbcB), and the SbcCD nuclease play a redundant role in vivo, which is essential for the recombination activity of the RecBC complex during UV repair.
منابع مشابه
Role of the RecBCD recombination pathway in Salmonella virulence.
Mutants of Salmonella enterica lacking the RecBC function are avirulent in mice and unable to grow inside macrophages (N. A. Buchmeier, C. J. Lipps, M. Y. H. So, and F. Heffron, Mol. Microbiol. 7:933-936, 1993). The virulence-related defects of RecBC(-) mutants are not suppressed by sbcB and sbcCD mutations, indicating that activation of the RecF recombination pathway cannot replace the virulen...
متن کاملEscherichia coli strains lacking protein HU are UV sensitive due to a role for HU in homologous recombination.
hupA and hupB encode the alpha and beta subunits of the Escherichia coli histone-like protein HU. Here we show that E. coli hup mutants are sensitive to UV in the rec+ sbc+, recBC sbcA, recBC sbcBC, umuDC, recF, and recD backgrounds. However, hupAB mutations do not enhance the UV sensitivity of resolvase-deficient recG ruvA strains. hupAB uvrA and hupAB recG strains are supersensitive to UV. hu...
متن کاملFunctions of multiple exonucleases are essential for cell viability, DNA repair and homologous recombination in recD mutants of Escherichia coli.
Heterotrimeric RecBCD enzyme unwinds and resects a DNA duplex containing blunt double-stranded ends and directs loading of the strand-exchange protein RecA onto the unwound 3'-ending strand, thereby initiating the majority of recombination in wild-type Escherichia coli. When the enzyme lacks its RecD subunit, the resulting RecBC enzyme, active in recD mutants, is recombination proficient althou...
متن کاملBiochemical and physical characterization of exonuclease V from Escherichia coli. Comparison of the catalytic activities of the RecBC and RecBCD enzymes.
Biochemical evidence is presented that confirms exonuclease V of Escherichia coli consists of three distinct subunits encoded by the recB, recC, and recD genes. The recD gene encodes a Mr 60,000 polypeptide and physically maps 3' to the recB structural gene. The role of the recD subunit in exonuclease V function has been examined by comparing the catalytic activities of the purified RecBCD enzy...
متن کاملEscherichia coli xonA (sbcB) mutants enhance illegitimate recombination.
Mutations of Escherichia coli K-12 were isolated that increase the frequency of deletion formation. Three of these mutations map to the gene sbcB at 43.5 min on the E. coli chromosome. Two types of mutations at sbcB have been previously defined: sbcB-type that suppress both the UV sensitivity and recombination deficiency of recBC mutants, and xonA-type that suppress only the UV sensitivity. Bot...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of bacteriology
دوره 181 19 شماره
صفحات -
تاریخ انتشار 1999