The recombination hotspot Chi is recognized by the translocating RecBCD enzyme as the single strand of DNA containing the sequence 5′-GCTGGTGG-3′
AUTOR(ES)
Bianco, Piero R.
FONTE
The National Academy of Sciences of the USA
RESUMO
The RecBCD enzyme of Escherichia coli functions in the seemingly disparate roles of homologous recombination and the degradation of DNA. Which of these two roles it assumes is regulated by the 8-base recombination hotspot, Chi. Using double-stranded DNA substrates that are heteroduplex at the Chi locus we have established the determinants for Chi recognition. Our results show that an actively translocating RecBCD enzyme requires only the sequence information in the 5′-GCTGGTGG-3′-containing strand to recognize and to be regulated by Chi. Furthermore, the RecBCD enzyme can translocate through DNA heteroduplex bubbles as large as 22 bases, and still recognize a Chi sequence embedded in this region. This implies that recognition of Chi occurs following the unwinding of the DNA.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=21222Documentos Relacionados
- RecBCD enzyme is altered upon cutting DNA at a chi recombination hotspot.
- Strand specificity of DNA unwinding by RecBCD enzyme.
- Regulation of homologous recombination: Chi inactivates RecBCD enzyme by disassembly of the three subunits
- Reversible inactivation of the Escherichia coli RecBCD enzyme by the recombination hotspot chi in vitro: evidence for functional inactivation or loss of the RecD subunit.
- Specific inhibition of the E.coli RecBCD enzyme by Chi sequences in single-stranded oligodeoxyribonucleotides