Sortase-mediated protein ligation: a new method for protein engineering

J Am Chem Soc. 2004 Mar 10;126(9):2670-1. doi: 10.1021/ja039915e.


Sortase (SrtA), a transpeptidase from Staphylococcus aureus, catalyzes a cell-wall sorting reaction at an LPXTG motif by cleaving between threonine and glycine and subsequently joining the carboxyl group of threonine to an amino group of pentaglycine on the cell wall peptidoglycan. We have applied this transpeptidyl activity of sortase to in vitro protein ligation. We found that in the presence of sortase, protein/peptide with an LPXTG motif can be specifically ligated to an aminoglycine protein/peptide via an amide bond. Additionally, sortase can even conjugate substrates such as (d)-peptides, synthetic branched peptides, and aminoglycine-derivatized small molecules to the C terminus of a recombinant protein. The sortase-mediate protein ligation is robust, specific, and easy to perform, and can be widely applied to specific protein conjugation with polypeptides or molecules of unique biochemical and biophysical properties.

MeSH terms

  • Amino Acid Sequence
  • Aminoacyltransferases / chemistry*
  • Aminoacyltransferases / metabolism
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism
  • Cysteine Endopeptidases
  • Green Fluorescent Proteins
  • Luminescent Proteins / chemistry
  • Molecular Sequence Data
  • Peptides / chemical synthesis
  • Peptides / chemistry*
  • Peptides / metabolism
  • Protein Engineering / methods*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization


  • Bacterial Proteins
  • Luminescent Proteins
  • Peptides
  • Green Fluorescent Proteins
  • Aminoacyltransferases
  • sortase A
  • Cysteine Endopeptidases