Structure of FokI has implications for DNA cleavage.
FokI is a member an unusual class of restriction enzymes that recognize a specific DNA sequence and cleave nonspecifically a short distance away from that sequence. FokI consists of an N-terminal DNA recognition domain and a C-terminal cleavage domain. The bipartite nature of FokI has led to the development of artificial enzymes with novel specificities. We have solved the structure of FokI to 2.3 A resolution. The structure reveals a dimer, in which the dimerization interface is mediated by the cleavage domain. Each monomer has an overall conformation similar to that found in the FokI-DNA complex, with the cleavage domain packing alongside the DNA recognition domain. In corroboration with the cleavage data presented in the accompanying paper in this issue of Proceedings, we propose a model for FokI DNA cleavage that requires the dimerization of FokI on DNA to cleave both DNA strands.
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Structural Biology Program, Department of Physiology and Biophysics, Box 1677, 1425 Madison Avenue, Mount Sinai School of Medicine, New York, NY 10029, USA.
Bitinaite
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Schildkraut
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Aggarwal
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D000595:Amino Acid Sequence; D001483:Base Sequence; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D015252:Deoxyribonucleases, Type II Site-Specific / Q000737:chemistry / Q000378:metabolism*; D019281:Dimerization; D006868:Hydrolysis; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation
D004247:DNA; C035042:endodeoxyribonuclease FokI; D015252:Deoxyribonucleases, Type II Site-Specific