DNA binding and cleavage by the HNH homing endonuclease I-HmuI.
|Title||DNA binding and cleavage by the HNH homing endonuclease I-HmuI.|
|Publication Type||Journal Article|
|Year of Publication||2004|
|Authors||Shen BW, Landthaler M, Shub DA, Stoddard BL|
|Journal||Journal of molecular biology|
|Date Published||2004 Sep 3|
|Keywords||Amino Acid Sequence, Base Sequence, Binding Sites, Colicins, Crystallography, X-Ray, Deoxyribonuclease I, DNA, Metals, Models, Molecular, Molecular Sequence Data, Protein Binding, Protein Structure, Tertiary, Sequence Alignment|
The structure of I-HmuI, which represents the last family of homing endonucleases without a defining crystallographic structure, has been determined in complex with its DNA target. A series of diverse protein structural domains and motifs, contacting sequential stretches of nucleotide bases, are distributed along the DNA target. I-HmuI contains an N-terminal domain with a DNA-binding surface found in the I-PpoI homing endonuclease and an associated HNH/N active site found in the bacterial colicins, and a C-terminal DNA-binding domain previously observed in the I-TevI homing endonuclease. The combination and exchange of these features between protein families indicates that the genetic mobility associated with homing endonucleases extends to the level of independent structural domains. I-HmuI provides an unambiguous structural connection between the His-Cys box endonucleases and the bacterial colicins, supporting the hypothesis that these enzymes diverged from a common ancestral nuclease.
|Alternate Journal||J. Mol. Biol.|