Protein splicing of a temperature‐dependent intein from an extreme thermophile (768.10)

Inteins are intervening polypeptides that self‐catalyze their own excision from the flanking polypeptides, or exteins, in a process called protein splicing. We are studying an intein that interrupts genes from the archaebacteria Pyrococcus abyssi. The Pyrococcus abyssi (Pab) PolII intein only splices at elevated temperatures. The intein contains an N‐terminal cysteine and is preceded by an asparagine in the N‐extein at the ‐1 position. We have shown that protein cleavage occurs independent of the canonical splicing mechanism when the protein contains an alanine in place of the cysteine and an aspartate in place of the asparagine. In addition, we created a split version of the intein to determine whether when split into two fragments and recombined, the intein is capable of undergoing trans splicing. Grant Funding Source : Supported by the National Science Foundation, the Dreyfus Foundation, and The BD Corporation