Part:BBa_T2016

S-tag head domain (KETAAAKFERQHMDS)

This is a S-tag head domain designed to be at the N-terminus of a protein. S-tags are a type of affinity tag that can be used to purify and/or measure the quantity of proteins.

Usage and Biology

The protease subtilisin cleaves a single peptide bond in native RNase A. The resulting two fragments are the S-peptide (residues 1-20 of RNase A) and the S-protein (residues 21-124 of RNase A). These two fragments noncovalently associate to form a functional ribonuclease, called RNase S.

The S-tag system was developed based on the high affinity between the S-peptide and S-protein of RNase S. The S-tag is derived from the first 15 residues of the S-peptide and therefore was originally called S15Kim93. It binds with high affinity to the S-protein (or S-fragment) of RNase A. Elution from the S-protein occurs at low pH. An RNase A assay is possible for a quantitative assay of protein expression levels. Colorimetric assays are also available for detection of S-tagged proteins without the use of an antibody.

The S-tag can be used at the N- or C-terminus or internal to a protein of interest.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  INCOMPATIBLE WITH RFC[12]

  Illegal NotI site found at 16
  
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  INCOMPATIBLE WITH RFC[1000]

  Illegal BsaI.rc site found at 10