A promiscuous split intein with expanded protein engineering applications. Author Adam Stevens, Giridhar Sekar, Neel Shah, Anahita Mostafavi, David Cowburn, Tom Muir Publication Year 2017 Type Journal Article Abstract The protein -splicing (PTS) activity of naturally split inteins has found widespread use in chemical biology and biotechnology. However, currently used naturally split inteins suffer from an "extein dependence," whereby residues surrounding the splice junction strongly affect splicing efficiency, limiting the general applicability of many PTS-based methods. To address this, we describe a mechanism-guided protein engineering approach that imbues ultrafast DnaE split inteins with minimal extein dependence. The resulting "promiscuous" inteins are shown to be superior reagents for protein cyclization and protein semisynthesis, with the latter illustrated through the modification of native cellular chromatin. The promiscuous inteins reported here thus improve the applicability of existing PTS methods and should enable future efforts to engineer promiscuity into other naturally split inteins. Keywords Bacterial Proteins, Models, Molecular, Protein Engineering, Inteins, Nostoc, Protein Splicing, Synechocystis, Biotechnology, DNA Polymerase III, Exteins Journal Proc Natl Acad Sci U S A Volume 114 Issue 32 Pages 8538-8543 Date Published 2017 Aug 08 ISSN Number 1091-6490 DOI 10.1073/pnas.1701083114 Alternate Journal Proc Natl Acad Sci U S A PMCID PMC5559002 PMID 28739907 PubMedPubMed CentralGoogle ScholarBibTeXEndNote X3 XML