AOA1 (ataxia oculomotor apraxia-1) results from mutations in aprataxin, a component of DNA strand break repair that removes AMP from 5'-termini. In the present article, we provide an overview of this disease and review recent experiments demonstrating that short-patch repair of oxidative single-strand breaks in AOA1 cell extracts bypasses the point of aprataxin action and stalls at the final st...

Accurate pairing of DNA strands is essential for repair of DNA double-strand breaks (DSBs). How cells achieve accurate annealing when large regions of single-strand DNA are unpaired has remained unclear despite many efforts focused on understanding proteins, which mediate this process. Here we report the crystal structure of a single-strand annealing protein [DdrB (DNA damage response B)] in co...

Analysis of duck hepatitis B viral DNA by gel electrophoresis, Southern blotting, and binding to benzoylated naphthoylated DEAE-cellulose showed that a protein is bound to the minus-strand virion DNA as well as to the full-length single strand, minus-strand species, and minus-strand DNA intermediates isolated from replicating complexes present in infected duck liver. By utilizing a modified did...

Growing monolayer COLO320 human cells having a 30- to 40-fold amplification of a MYC domain were pulse treated for 15 min with increasing doses of bleomycin (BLM). Cellular DNA was extracted at the end of the BLM treatment or after an interval of 30 min, during which the cells were allowed to repair the DNA damage at 37 degrees C in culture medium without BLM. Damage and repair in total cellula...

The DNA Polymerase III holoenzyme forms initiation complexes on primed DNA in an ATP-dependent reaction. We demonstrate that the nonhydrolyzable ATP analog, ATP gamma S, supports the formation of an isolable leading strand complex that loads and replicates the lagging strand only in the presence of ATP, beta, and the single-stranded DNA binding protein. The single endogenous DnaX complex within...

Escherichia coli C cells, unifilarly substituted with 5-bromouracil (BrUra) were 2-25 times as sensitive as unsubstituted cells to killing by gamma-irradiation under aerobic conditions. The yield of DNA double-strand breaks in BrUra-substituted cells was increased by a factor only 1-55, suggesting that other lesions also contribute to cell-killing. Alkaline sucrose density gradient analysis of ...

Under conditions favoring single-strand transformation, the two complementary strands of Bacillus subtilis DNA, separated by differential complexing with polyriboguanylic acid, have identical transforming activity. Moreover separated single strands, upon renaturation with unmarked (recipient) DNA, form heteroduplex molecules with similar double-strand transformin activity. These findings bear u...

The single-stranded DNA-binding protein of Escherichia coli significantly alters the strand assimilation reaction catalyzed by recA protein [McEntee, K., Weinstock, G. M. & Lehman, I. R. (1979) Proc. Natl. Acad. Sci. USA 76, 2615--2619]. The binding protein (i) increases the rate and extent of strand assimilation into homologous duplex DNA, (ii) enhances the formation of a complex between recA ...

In eukaryotic cells, RAD52 protein plays a central role in genetic recombination and DNA repair by (i) promoting the annealing of complementary single-stranded DNA and (ii) stimulation of the RAD51 recombinase. The single-strand annealing domain resides in the N-terminal region of the protein and is highly conserved, whereas the nonconserved RAD51-interaction domain is located in the C-terminal...

Third-generation DNA sequencing has enabled of long, unamplified fragments with minimal steps. Direct ssDNA or RNA gives valuable insights like base-level modifications, phosphoramidite synthesis yield estimates and strand quality analysis, without the need to add complimentary strand. single-stranded nucleic acid species is challenging as they are non-compatible double-stranded adapters...