I-SceI recognition sequence (I-SceI site)

The I-SceI recognition sequence is a highly specific 18-base pair asymmetric DNA sequence (5'-TAGGGATAACAGGGTAAT-3') that serves as the molecular target for the I-SceI homing endonuclease (Puchta et al., 1993; PubMed: 8303246). Originally discovered in the mitochondria of Saccharomyces cerevisiae, this sequence is statistically absent from the human and mouse genomes, making it an invaluable tool for inducing site-specific double-strand breaks in experimental models (Belfort & Roberts, 1997; PubMed: 9254690). When the I-SceI enzyme is introduced into cells containing this sequence, it generates a precise break that triggers cellular DNA damage response pathways, such as non-homologous end joining and homology-directed repair (Rouet et al., 1994; PubMed: 8196772). While not a natural therapeutic target, the I-SceI system is widely employed in gene therapy research to study gene correction, evaluate genome editing efficiency, and develop 'kill-switch' mechanisms for engineered cells (Porteus & Baltimore, 2003; PubMed: 12783001). The interaction is characterized by extreme specificity, although therapeutic application is limited by the need to pre-integrate the sequence into the genome and the potential immunogenicity of the bacterial enzyme. Understanding the repair outcomes at this DNA sequence is fundamental for advancing precision medicine, particularly in the development of safer and more efficient gene-editing technologies.

Other names

I-SceI recognition siteomega-nuclease recognition siteI-SceI target sequenceGenomic double-stranded DNA containing the I-SceI recognition sequence

Site-specific cleavage of the phosphodiester backbone by the I-SceI endonuclease, creating a double-strand break with 4-bp 3' overhangs (PubMed: 8303246).