DNA binding and helicase domains of the Escherichia coli recombination protein RecG.
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.
Mahdi
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Department of Genetics, University of Nottingham, Queens Medical Centre, Nottingham NG7 2UH, UK.
McGlynn
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P
Levett
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Lloyd
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RG
D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D004265:DNA Helicases / Q000378:metabolism*; D004260:DNA Repair; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D006639:Histidine / Q000737:chemistry; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D015202:Protein Engineering; D011995:Recombination, Genetic; D017384:Sequence Deletion; D016324:Sequence Tagged Sites
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D010446:Peptide Fragments; C071446:RecG protein, E coli; D006639:Histidine; D004265:DNA Helicases