Fig. 1.

The TMPRSS2 protein and the p.Val160Met variant

The TMPRSS2 protein is composed of a cytoplasmic region (residues 1–84), a transmembrane region (TM, residues 85–105) and an extracellular region (residues 106–492). The latter is composed of three domains: the LDLR class A (residues 112–149), the scavenger receptor cysteine-rich domain (SRCR) (residues 150–242) and the Peptidase S1 (residues 256–489), which contains the protease active site: residues His296, Asp345 and Ser441. The three-dimensional structure of the extracellular region residues 145–491 corresponding to domains SRCR-2 (in green) and Peptidase S1 (in blue) is presented. Valine 160 (Val 160, depicted as a red sphere on the cartoon), which harbours variant p.Val160Met, occurs in the SRCR domain and spatially far from the TMPRSS2 catalytic site (mapped onto the surface of TMPRSS2).