The following proteins have been shown to be evolutionary related [1,2,3]:

• Epimorphin (or syntaxin 2), a mammalian mesenchymal protein which plays an essential role in epithelial morphogenesis.
• Syntaxin 1A (also known as antigen HPC-1) and syntaxin 1B which are synaptic proteins which may be involved in docking of synaptic vesicles at presynaptic active zones.
• Syntaxin 3.
• Syntaxin 4, which is potentially involved in docking of synaptic vesicles at presynaptic active zones.
• Syntaxin 5, which mediates endoplasmic reticulum to golgi transport.
• Syntaxin 6, which is involved in intracellular vesicle trafficking.
• Syntaxin 7.
• Yeast PEP12 (or VPS6) which is required for the transport of proteases to the vacuole.
• Yeast SED5 which is required for the fusion of transport vesicles with the Golgi complex.
• Yeast SSO1 and SSO2 which are required for vesicle fusion with the plasma membrane.
• Yeast VAM3, which is required for vacuolar assembly.
• Arabidopsis thaliana protein KNOLLE which may be involved in cytokinesis.
• Caenorhabditis elegans hypothetical proteins F35C8.4, F48F7.2, F55A11.2 and T01B11.3.

The above proteins share the following characteristics: a size ranging from 30 Kd to 40 Kd; a C-terminal extremity which is highly hydrophobic and is probably involved in anchoring the protein to the membrane; a central, well conserved region, which seems to be in a coiled-coil conformation.

The pattern specific for this family is based on the most conserved region of the coiled coil domain.