Domain organization and metal ion requirement of the Type IIS restriction endonuclease MnlI.
A two-domain structure of the Type IIS restriction endonuclease MnlI has been identified by limited proteolysis. An N-terminal domain of the enzyme mediates the sequence-specific interaction with DNA, whereas a monomeric C-terminal domain resembles bacterial colicin nucleases in its requirement for alkaline earth as well as transition metal ions for double- and single-stranded DNA cleavage activities. The results indicate that the fusion of the non-specific HNH-type nuclease to the DNA binding domain had transformed MnlI into a Mg(2+)-, Ni(2+)-, Co(2+)-, Mn(2+)-, Zn(2+)-, Ca(2+)-dependent sequence-specific enzyme. Nevertheless, MnlI retains a residual single-stranded DNA cleavage activity controlled by its C-terminal colicin-like nuclease domain.
Kriukiene
Edita
E
Institute of Biotechnology, Graiciuno 8, Vilnius LT-02241, Lithuania. ediga@ibt.lt
D000595:Amino Acid Sequence; D001665:Binding Sites; D002413:Cations, Divalent / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D010449:Peptide Mapping; D011487:Protein Conformation
D002413:Cations, Divalent; D004277:DNA, Single-Stranded; D008670:Metals; C052155:endodeoxyribonuclease MnlI; D015252:Deoxyribonucleases, Type II Site-Specific