Protein Splicing and Related Forms of Protein Autoprocessing

Abstract

Protein splicing is a form of posttranslational processing that consists of the excision of an intervening polypeptide sequence, the intein, from a protein, accompanied by the concomitant joining of the flanking polypeptide sequences, the exteins, by a peptide bond. It requires neither cofactors nor auxiliary enzymes and involves a series of four intramolecular reactions, the first three of which occur at a single catalytic center of the intein. Protein splicing can be modulated by mutation and converted to highly specific self-cleavage and protein ligation reactions that are useful protein engineering tools. Some of the reactions characteristic of protein splicing also occur in other forms of protein autoprocessing, ranging from peptide bond cleavage to conjugation with nonprotein moieties. These mechanistic similarities may be the result of convergent evolution, but in at least one case-hedgehog protein autoprocessing-there is definitely a close evolutionary relationship to protein splicing.

Making the most of affinity tags

“…Finally, it should be noted that self-processing fusion partners derived from inteins (protein introns that autocatalytically splice from their host proteins) represent an alternative to conventional proteolytic cleavage in trans [35]. However, intein-mediated cleavage has not yet been tested in a high-throughput context.…”

Diels–Alder Ligation of Peptides and Proteins

“…The intein itself is the catalyst of the splicing reaction and so far over 100 different inteins have been identified from diverse organisms. [51][52] N-Extein Elucidations of the protein splicing mechanism have directed the design of engineered inteins that perform single splice-and-junction cleavage under specific conditions. [53] These inteins, when fused to a particular protein either at its C or N terminus, may lead to the generation of a reactive C-terminal thioester or an N-terminal cysteine, respectively.…”

Solution structure of DnaE intein from Nostoc punctiforme: Structural basis for the design of a new split intein suitable for site‐specific chemical modification

“…Protein trans-splicing is a promising tool for post-translational ligation of protein fragments [1][2][3]. Protein splicing is a self-catalytic reaction catalyzed by an intervening sequence in a host protein, termed an intein, which ligates the flanking protein sequences, termed exteins, by a peptide bond and concomitantly excises itself from the host protein [3].…”