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 alpha-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.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2475608 | PMC |
| http://dx.doi.org/10.1093/nar/gkn333 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Interdomain communication in the endonuclease/motor subunit of type I restriction-modification enzyme EcoR124I.
J Mol Model
July 2014
Institute of Nanobiology and Structural Biology, Global Change Research Center, Academy of Sciences of the Czech Republic, Zamek 136, 373 33, Nove Hrady, Czech Republic.
Restriction-modification systems protect bacteria from foreign DNA. Type I restriction-modification enzymes are multifunctional heteromeric complexes with DNA-cleavage and ATP-dependent DNA translocation activities located on endonuclease/motor subunit HsdR. The recent structure of the first intact motor subunit of the type I restriction enzyme from plasmid EcoR124I suggested a mechanism by which stalled translocation triggers DNA cleavage via a lysine residue on the endonuclease domain that contacts ATP bound between the two helicase domains.
View Article and Find Full Text PDFA RecB-family nuclease motif in the Type I restriction endonuclease EcoR124I.
Nucleic Acids Res
July 2008
Institute of Microbiology v.v.i., Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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 alpha-helix.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!