 Parvulin

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Parvulin, a 92-amino acid protein discovered in E. coli in 1994, is the smallest known protein with prolyl isomerase activity, which catalyzes the "cis"-"trans" isomerization of proline peptide bonds.Although parvulin has no homology with larger prolyl isomerases such as cyclophilin and FKBP, it does share structural features with subdomains of other proteins involved in preparing secreted proteins for export from the cell.