The mechanism of protein splicing and its modulation by mutation.
Protein splicing results in the expression of two mature proteins from a single gene. After synthesis of a precursor protein, an internal segment (the intein) is excised and the external domains are joined together. A self-catalyzed mechanism for this cleavage-ligation reaction is presented, based on mutagenesis data and analysis of splicing intermediates. Mutations were used to block various steps in the protein splicing pathway, allowing each isolated step to be studied independently. A linear ester intermediate was identified and functional roles for the four conserved splice junction residues were determined. Understanding the mechanism of protein splicing provides a basis for protein engineering studies. For example, inteins can be constructed which fail to splice, but instead cleave the peptide bond at a chosen splice junction.
Xu
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New England Biolabs, Inc., Beverly, MA 01915, USA.
Perler
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D001426:Bacterial Proteins / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D003545:Cysteine / Q000494:pharmacology; D004259:DNA-Directed DNA Polymerase / Q000235:genetics; D019811:Hydroxylamine; D006898:Hydroxylamines / Q000494:pharmacology; D058619:Maltose-Binding Proteins; D008957:Models, Genetic; D016254:Mutagenesis, Insertional; D009154:Mutation; D011498:Protein Precursors / Q000235:genetics*; D019154:Protein Splicing / Q000235:genetics / Q000502:physiology*; D011994:Recombinant Proteins / Q000235:genetics; D014335:Tropomyosin / Q000235:genetics
D001426:Bacterial Proteins; D002352:Carrier Proteins; D006898:Hydroxylamines; D058619:Maltose-Binding Proteins; D011498:Protein Precursors; D011994:Recombinant Proteins; D014335:Tropomyosin; D019811:Hydroxylamine; D004259:DNA-Directed DNA Polymerase; D003545:Cysteine