A combinatorial approach to create artificial homing endonucleases cleaving chosen sequences.
Meganucleases, or homing endonucleases (HEs) are sequence-specific endonucleases with large (>14 bp) cleavage sites that can be used to induce efficient homologous gene targeting in cultured cells and plants. These findings have opened novel perspectives for genome engineering in a wide range of fields, including gene therapy. However, the number of identified HEs does not match the diversity of genomic sequences, and the probability of finding a homing site in a chosen gene is extremely low. Therefore, the design of artificial endonucleases with chosen specificities is under intense investigation. In this report, we describe the first artificial HEs whose specificity has been entirely redesigned to cleave a naturally occurring sequence. First, hundreds of novel endonucleases with locally altered substrate specificity were derived from I-CreI, a Chlamydomonas reinhardti protein belonging to the LAGLIDADG family of HEs. Second, distinct DNA-binding subdomains were identified within the protein. Third, we used these findings to assemble four sets of mutations into heterodimeric endonucleases cleaving a model target or a sequence from the human RAG1 gene. These results demonstrate that the plasticity of LAGLIDADG endonucleases allows extensive engineering, and provide a general method to create novel endonucleases with tailored specificities.
Smith
Julianne
J
CELLECTIS S.A., 102 route de Noisy, 93235 Romainville, France.
Grizot
Sylvestre
S
Arnould
Sylvain
S
Duclert
Aymeric
A
Epinat
Jean-Charles
JC
Chames
Patrick
P
Prieto
Jesús
J
Redondo
Pilar
P
Blanco
Francisco J
FJ
Bravo
Jerónimo
J
Montoya
Guillermo
G
Pâques
Frédéric
F
Duchateau
Philippe
P
D004247:DNA / Q000378:metabolism; D004262:DNA Restriction Enzymes / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D003627:Data Interpretation, Statistical; D019281:Dimerization; D016654:Genes, RAG-1; D006801:Humans; D009154:Mutation; D009711:Nucleotides / Q000378:metabolism; D019151:Peptide Library; D015202:Protein Engineering / Q000379:methods*; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity
D009711:Nucleotides; D019151:Peptide Library; D004247:DNA; D004262:DNA Restriction Enzymes; C048901:endodeoxyribonuclease CreI