Part:BBa_K380009

Protein A Z-domain

Staphylococcal protein A (SpA), is produced from bacterium Staphylococcus aureus. We have worked with a Z domain of SpA that is an engineered analogue of the IgG-binding domain B. The Z domain has three alpha helices that are arranged in an antiparallel three-helix bundle. The domain has no disulfide bonds and is 72 amino acid residues long.

Reference: http://www-nmr.cabm.rutgers.edu/photogallery/proteins/htm/page16.htm

Staphylococcal protein A (SPA) is often used as an immunological tool. It it very useful when performing affinity chromatography purifications of example recombinant proteins. This is possible since Protein A can bind immunoglobulins. This protein-protein-interaction is very well studied. Protein A has five homologous domains that have strong interaction capabilities to the Fc region of the human antibody IgG.

Domain Z is one of the five domains that we used in our iGEM project. It is a monovalent SPA analogue that is based on domain B. The Z domain has unique folding properties since it is only 7 kDa. It thus has very little effect on the fusion partner’s folding into a native conformation. Protein existence: Evidence at protein level http://www.uniprot.org/uniprot/P38507

Reference:

• All individual domains of staphylococcal protein A show Fab binding. Jansson B, Uhlén M, Nygren PA. FEMS Immunol Med Microbiol. 1998 Jan;20(1):69-78.
• http://www.gelifesciences.com/aptrix/upp01077.nsf/Content/Products?OpenDocument&parentid=976048&moduleid=38878&zone=Proteomics

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BglII site found at 44
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]