Identification and purification of a single-stranded-DNA-specific exonuclease encoded by the recJ gene of Escherichia coli.
AUTOR(ES)
Lovett, S T
RESUMO
The Escherichia coli recJ gene product was overproduced using a plasmid that carries the recJ gene downstream of a strong regulatable promoter and a strong ribosome-binding site. Overexpression of recJ produced a concomitant increase in the levels of single-stranded-DNA-specific nuclease activity present in crude cell extracts. This nuclease activity was purified to homogeneity and found to reside in a 60-kDa polypeptide. This polypeptide was induced with recJ overexpression and had the size and N-terminal amino acid sequence identical to the predicted RecJ protein sequence. The RecJ nuclease degraded linear single-stranded DNA but did not have exonuclease activity on linear double-stranded substrates or endonuclease activity on either single-stranded or double-stranded substrates. The RecJ exonuclease had greater activity on duplex DNA molecules with 5'-rather than 3'-single-stranded tails.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=286970Documentos Relacionados
- Mutational Analysis of the RecJ Exonuclease of Escherichia coli: Identification of Phosphoesterase Motifs
- Cloning of the Escherichia coli recJ chromosomal region and identification of its encoded proteins.
- A Thermostable Single-Strand DNase from Methanococcus jannaschii Related to the RecJ Recombination and Repair Exonuclease from Escherichia coli
- IF3-mediated suppression of a GUA initiation codon mutation in the recJ gene of Escherichia coli.
- Genetic analysis of the recJ gene of Escherichia coli K-12.