The influence of extein residues on the protein splicing of three Pyrococcus abyssi inteins

Abstract

Protein splicing is catalyzed by an intervening polypeptide, called an intein. Inteins facilitate their own excision from the flanking polypeptides, called exteins, as well as the ligation of the exteins. Three inteins interrupt the ribonucleotide reductase of the extreme thermophile Pyrococcus abyssi. We have separately over‐expressed each intein in E. coli as a fusion protein with flanking affinity domains. By site directed mutagenesis, we have altered the sequences flanking each intein to determine the flexibility of the intein insertion site. We have also made mutations to residues suspected of catalyzing the splicing steps in each intein. We plan to study the influence of these mutations on the rate and extent of splicing. This material is based upon work supported by the National Science Foundation under Grant No. 0320824 and CAREER grant No. 0447647.