Nostoc punctiforme DnaE split intein (Npu DnaE)

The Nostoc punctiforme (Npu) DnaE split intein is a highly efficient protein element derived from the cyanobacterium Nostoc punctiforme that facilitates protein trans-splicing (PTS). In this process, the N-terminal (IntN) and C-terminal (IntC) fragments of the intein spontaneously associate with high affinity to form a catalytically active domain, which then excises itself while ligating the flanking protein sequences, known as exteins, with a peptide bond (Iwai et al., 2006, FEBS Lett). This specific intein is noted for its exceptionally fast splicing kinetics and high tolerance for various extein sequences, making it a premier tool in chemical biology and protein engineering (Shah et al., 2011, J Am Chem Soc). In the realm of therapeutics, Npu DnaE is primarily employed in gene therapy to overcome the limited cargo capacity of viral delivery vehicles like Adeno-associated virus (AAV). By splitting large therapeutic proteins, such as the CRISPR/Cas9 system or the dystrophin protein, into two fragments delivered by separate vectors, the functional protein can be reconstituted in vivo (Li et al., 2008, Hum Gene Ther). While it is not a target for traditional small-molecule inhibition, its use as a therapeutic platform necessitates careful consideration of the immunogenic potential of bacterial proteins in human patients (Tornabene et al., 2019, Sci Transl Med). Furthermore, the efficiency of the splicing reaction in different tissue types remains a critical factor for the success of intein-mediated dual-vector therapies (Zhu et al., 2010, J Biol Chem).

Other names

Npu DnaE split inteinNpu split inteinNostoc punctiforme DnaE intein

Protein trans-splicing (PTS) mediated by the spontaneous, non-covalent association of split intein fragments to catalyze peptide bond formation between flanking exteins.