Protein Splicing

Abstract

Protein splicing is a posttranslational processing event that involves the precise removal of an internal polypeptide segment, termed an intein, from a precursor protein with the concomitant ligation of the flanking polypeptide sequences, termed exteins. Reminiscent of some RNA introns (Group I), inteins have been shown to self-catalyze the splicing event without the requirement of external energy or protein cofactors. The mechanism of protein self-splicing has been elucidated by the identification of key catalytic amino acid residues and intermediates. Mutation of these catalytic amino acid residues has permitted the modulation of inteins for use in a variety of molecular biology and biotechnology applications that include protein purification, ligation, cyclization, gene therapy approaches, and selenoprotein production.