The most interesting similarity found was to the structure of theHelicobacter pylori protein Tip-α (Tumor necrosis factor α (TNF-α) inducing protein) (PDB IDs: 2WCQ, 3VNC) with an RMSD of 3.08 Å over the length of 136 amino acids. Tip-α is an unusual virulence factor, being able to penetrate gastric cells and stimulate the production of the TNF- α and simultaneously activate the NF-κB pathway [17], finally resulting in a strong carcinogenic effect. Tip-α is highly expressed during bacterial infection [22] and forms homodimers in its active state.
Finally, another pairwise alignment between the structure of calcium dodecin (Rv0397) from Mycobacterium tuberculosis (PDB ID: 3ONR) and the structure of FTT_1539 had an RMSD of 2.19 Å over the length of 137 amino acids. Calcium dodecin is also classified as a member of the SHS2 clan and is involved in secretion and signaling of proteins that help regulate the life cycle of bacteria [23]. The structural fold of calcium dodecin allows it to form a pocket-like motif which binds calcium and is similar to metal or flavin binding sites [23].