title: The P1' specificity of tobacco etch virus protease.
abstract: Affinity tags have become indispensable tools for protein expression and purification. Yet, because they have the potential to interfere with structural and functional studies, it is usually desirable to remove them from the target protein. The stringent sequence specificity of the tobacco etch virus (TEV) protease has made it a useful reagent for this purpose. However, a potential limitation of TEV protease is that it is believed to require a Gly or Ser residue in the P1' position of its substrates to process them with reasonable efficiency. Consequently, after an N-terminal affinity tag is removed by TEV protease, the target protein will usually retain a non-native Ser or Gly residue on its N-terminus, and in some cases this may affect its biological activity. To investigate the stringency of the requirement for Gly or Ser in the P1' position of a TEV protease recognition site, we constructed 20 variants of a fusion protein substrate with an otherwise optimal recognition site, each containing a different amino acid in the P1' position. The efficiency with which these fusion proteins were processed by TEV protease was compared both in vivo and in vitro. Additionally, the kinetic parameters K(M) and k(cat) were determined for a representative set of peptide substrates with amino acid substitutions in the P1' position. The results indicate that many side-chains can be accommodated in the P1' position of a TEV protease recognition site with little impact on the efficiency of processing.
authors.affiliation: Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, P.O. Box B, Frederick, MD 21702, USA.
authors.forename: Rachel B
authors.initials: RB
authors.lastname: Kapust
authors.forename: József
authors.initials: J
authors.lastname: Tözsér
authors.forename: Terry D
authors.initials: TD
authors.lastname: Copeland
authors.forename: David S
authors.initials: DS
authors.lastname: Waugh
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism*; D029968:Escherichia coli Proteins; D007700:Kinetics; D058619:Maltose-Binding Proteins; D008969:Molecular Sequence Data; D010445:Peptide Elongation Factors / Q000235:genetics / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D013379:Substrate Specificity; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D058619:Maltose-Binding Proteins; C070291:NusG protein, E coli; D010445:Peptide Elongation Factors; D010455:Peptides; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D010450:Endopeptidases; C099488:TEV protease