title: Synthetic two-piece and three-piece split inteins for protein trans-splicing.
abstract: Inteins are protein-intervening sequences that can self-excise and concomitantly splice together the flanking polypeptides. Two-piece split inteins capable of protein trans-splicing have been found in nature and engineered in laboratories, but they all have a similar split site corresponding to the endonuclease domain of the intein. Can inteins be split at other sites and do trans-splicing? After testing 13 split sites engineered into a Ssp DnaB mini-intein, we report the finding of three new split sites that each produced a two-piece split intein capable of protein trans-splicing. These three functional split sites are located in different loop regions between beta-strands of the intein structure, and one of them is just 11 amino acids from the beginning of the intein. Because different inteins have similar structures and similar beta-strands, these new split sites may be generalized to other inteins. We have also demonstrated for the first time that a three-piece split intein could function in protein trans-splicing. These findings have implications for intein structure-function, evolution, and uses in biotechnology.
authors.affiliation: Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4H7, Canada.
authors.forename: Wenchang
authors.initials: W
authors.lastname: Sun
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.forename: Xiang-Qin
authors.initials: XQ
authors.lastname: Liu
mesh_terms: D004926:Escherichia coli; D047668:Inteins / Q000235:genetics; D019154:Protein Splicing; D011506:Proteins / Q000235:genetics; D013329:Structure-Activity Relationship; D020040:Trans-Splicing
chemical_list: D011506:Proteins