Strand-specific mismatch correction in nuclear extracts of human and Drosophila melanogaster cell lines.
AUTOR(ES)
Holmes, J
RESUMO
Nuclear extracts derived from HeLa and Drosophila melanogaster KC cell lines have been found to correct single base-base mispairs within open circular DNA heteroduplexes containing a strand-specific, site-specific incision located 808 base pairs from the mismatch. Correction in both extract systems is strand specific, being highly biased to the incised DNA strand. Different mispairs within a homologous set of heteroduplexes were processed with different efficiencies (G.T greater than G.G approximately equal to A.C greater than C.C), and correction was accompanied by mismatch-dependent DNA synthesis localized to the region spanning the mispair and the strand break, thus demonstrating that mismatch recognition is associated with the repair reaction. Correction of each of these heteroduplexes was abolished by aphidicolin but was relatively insensitive to the presence of high concentrations of ddTTP, indicating probable involvement of alpha and/or delta class DNA polymerase(s). These findings suggest that higher eukaryotic cells possess a general, strand-specific mismatch repair system analogous to the Escherichia coli mutHLS and the Streptococcus pneumoniae hexAB pathways, systems that contribute in a major way to the genetic stability of these bacterial species.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=54423Documentos Relacionados
- An alkylation-tolerant, mutator human cell line is deficient in strand-specific mismatch repair.
- Purification and properties of a single strand-specific endonuclease from mouse cell mitochondria.
- Temperature-sensitive mouse cell factors for strand-specific initiation of poliovirus RNA synthesis.
- STRAND-SPECIFIC TRANSFER OF DONOR DNA DURING CONJUGATION IN E. coli*
- Gene-specific and strand-specific DNA repair in the G1 and G2 phases of the cell cycle.