The heptapeptide was discovered in Bacillus cereus which allows this microorganism to bind to glass. The recombinant tag developed from this natural precursor peptide binds to glass and can be removed by arginine, which is advantageous over imidazole, used for the elution of his-tagged proteins.

Akio KURODA laboratory, https://home.hiroshima-u.ac.jp/akbio/pg276.html