Mini-Intein Structures from Extremophiles Suggest a Strategy for Finding Novel Robust Inteins.
Hiltunen, M.K., Beyer, H.M., Iwai, H.(2021) Microorganisms 9
- PubMed: 34198729 
- DOI: https://doi.org/10.3390/microorganisms9061226
- Primary Citation of Related Structures:  
7OEC - PubMed Abstract: 
Inteins are prevalent among extremophiles. Mini-inteins with robust splicing properties are of particular interest for biotechnological applications due to their small size. However, biochemical and structural characterization has still been limited to a small number of inteins, and only a few serve as widely used tools in protein engineering. We determined the crystal structure of a naturally occurring Pol-II mini-intein from Pyrococcus horikoshii and compared all three mini-inteins found in the genome of P. horikoshii . Despite their similar sizes, the comparison revealed distinct differences in the insertions and deletions, implying specific evolutionary pathways from distinct ancestral origins. Our studies suggest that sporadically distributed mini-inteins might be more promising for further protein engineering applications than highly conserved mini-inteins. Structural investigations of additional inteins could guide the shortest path to finding novel robust mini-inteins suitable for various protein engineering purposes.
Organizational Affiliation: 
Institute of Biotechnology, HiLiFE, University of Helsinki, P.O. Box 56, 00014 Helsinki, Finland.