Methyl-directed repair of frameshift heteroduplexes in cell extracts from Escherichia coli.
AUTOR(ES)
Learn, B A
RESUMO
The methyl-directed DNA repair efficiency of a series of M13mp9 frameshift heteroduplexes 1, 2, or 3 unpaired bases was determined by using an in vitro DNA mismatch repair assay. Repair of hemimethylated frameshift heteroduplexes in vitro was directed to the unmethylated strand; was dependent on MutH, MutL, and MutS; and was equally efficient on base insertions and deletions. However, fully methylated frameshift heteroduplexes were resistant to repair, while totally unmethylated substrates were repaired with no strand bias. Hemimethylated 1-, 2-, or 3-base insertion and deletion heteroduplexes were repaired by the methyl-directed mismatch repair pathway as efficiently as the G.T mismatch. These results are consistent with earlier in vivo studies and demonstrate the involvement of methyl-directed DNA repair in the efficient prevention of frameshift mutations.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=210536Documentos Relacionados
- Methyl-directed repair of frameshift mutations in heteroduplex DNA.
- The Escherichia coli Methyl-Directed Mismatch Repair System Repairs Base Pairs Containing Oxidative Lesions
- Effects of High Levels of DNA Adenine Methylation on Methyl-Directed Mismatch Repair in ESCHERICHIA COLI
- Methyl-directed repair of DNA base-pair mismatches in vitro.
- Evidence for a previously undetected CpG methyl-directed restriction system in E. coli.
