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. 1997 Oct 1;25(19):3875–3880. doi: 10.1093/nar/25.19.3875

DNA binding and helicase domains of the Escherichia coli recombination protein RecG.

A A Mahdi 1, P McGlynn 1, S D Levett 1, R G Lloyd 1
PMCID: PMC146975  PMID: 9380511

Abstract

The Escherichia coli RecG protein is a unique junction-specific helicase involved in DNA repair and recombination. The C-terminus of RecG contains motifs conserved throughout a wide range of DNA and RNA helicases and it is thought that this C-terminal half of RecG contains the helicase active site. However, the regions of RecG which confer junction DNA specificity are unknown. To begin to assign structure-function relationships within RecG, a series of N- and C-terminal deletions have been engineered into the protein, together with an N-terminal histidine tag fusion peptide for purification purposes. Junction DNA binding, unwinding and ATP hydrolysis were disrupted by mutagenesis of the N-terminus. In contrast, C-terminal deletions moderately reduced junction DNA binding but almost abolished unwinding. These data suggest that the C-terminus does contain the helicase active site whereas the N-terminus confers junction DNA specificity.

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Selected References

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