Zinc Finger Chimera

Zinc Finger Chimera

Zinc finger protein chimera are chimeric proteins composed of a DNA-binding zinc finger protein domain and another domain through which the protein exerts its effect. The effector domain may be a transcriptional activator (A) or repressor (R), a methylation domain (M) or a nuclease (N).

Modification of the endogenous DNA-binding zinc finger domain is the basis of the most advanced field in construction of gene-specific artificial transcription factors. Linking together six ZFPs produces a target-site of 18-19 bp. Assuming specificity to that one sequence and that the sequence of the genome is random, 18 bp is long enough to be unique in all known genomes Indeed, the spacing between subsites becomes part of the target sequence due to restrictions in the flexibility of the protein which can be controlled. Targeting sites as small as 9 bp provides some degree of specificity, almost certainly attributable in some part to chromatin occlusion.