Long palindromes formed in Streptomyces by nonrecombinational intra-strand annealing
AUTOR(ES)
Qin, Zhongjun
FONTE
Cold Spring Harbor Laboratory Press
RESUMO
Long inverted repeats (palindromes) are ubiquitous among prokaryotic and eukaryotic genomes. Earlier work has implicated both DNA breaks and short inverted repeats (IRs) in the formation of long palindromes in yeast and Tetrahymena by a proposed mechanism of intramolecular recombination. Here we report that long-palindromic linear plasmids are formed in Streptomyces following double strand DNA breakage by a nonrecombinational intra-strand annealing process that also involves IRs. By modification of palindrome-generating linear plasmids and development of a novel procedure that enables the sequencing of palindrome junctions, we show that long-palindrome formation occurs by unimolecular intra-strand annealing of IRs followed by 3′ extension of the resulting DNA fold-back. The consequent hairpin structures serve as templates for synthesis of duplex linear plasmids containing long palindromes. We suggest that this model for long-palindrome formation in Streptomyces may represent a generally applicable mechanism for generating DNA palindromes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=316786Documentos Relacionados
- Specific tandem GG to TT base substitutions induced by acetaldehyde are due to intra-strand crosslinks between adjacent guanine bases.
- Slipped-strand DNAs formed by long (CAG)·(CTG) repeats: slipped-out repeats and slip-out junctions
- DNA strand annealing is promoted by the yeast Rad52 protein.
- Visualization of recombination intermediates produced by RAD52-mediated single-strand annealing
- Stability of intrastrand hairpin structures formed by the CAG/CTG class of DNA triplet repeats associated with neurological diseases.