Abstract
The Type I restriction-modification enzyme EcoR124I is an ATP-dependent endonuclease that uses dsDNA translocation to locate and cleave distant non-specific DNA sites. Bioinformatic analysis of the HsdR subunits of EcoR124I and related Type I enzymes showed that in addition to the principal PD-(E/D)xK Motifs, I, II and III, a QxxxY motif is also present that is characteristic of RecB-family nucleases. The QxxxY motif resides immediately C-terminal to Motif III within a region of predicted α-helix. Using mutagenesis, we examined the role of the Q and Y residues in DNA binding, translocation and cleavage. Roles for the QxxxY motif in coordinating the catalytic residues or in stabilizing the nuclease domain on the DNA are discussed.
Original language | English |
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Pages (from-to) | 3939-3949 |
Number of pages | 11 |
Journal | Nucleic Acids Research |
Volume | 36 |
Issue number | 12 |
Early online date | 29 May 2008 |
DOIs | |
Publication status | Published - 1 Jul 2008 |
ASJC Scopus subject areas
- Genetics