Structure of human t-plasminogen activator in complex with an inhibitor. The overall fold of this enzyme corresponds to the trypsin-like clan, also called PA clan. This fold displays two similar beta barrel-containing subdomains with the catalytic site between the barrels. Notably, this fold is not exclusive of serine-proteases, but is also present in certain viral cysteine-proteases. The catalytic site consists of a triad of residues in a charge relay system*, from Asp406 to His357 to Ser513. *See family S10 for a more detailed explanation of the charge relay system in a catalytic triad.
Structures are rendered as ribbons. Catalytic and catalytic metal-complexing residues are shown as neons. Inhibitors are displayed as space filling spheres.
Carbons are shown in light gray, hydrogens in cyan, oxygens in red, nitrogens in blue, and sulfurs in yellow.
Left-click and drag to rotate the protease. Right-click and drag up/down to zoom in/out. Click with both buttons and drag to move the protease. Use the upper bar to get different views and for display options. For a close-up of the catalytic site, choose the cat_site view.
Once you have clicked inside the structure window, you can use the keyboard to hide/show objects:
'1' toggles the ribbon. '2' toggles the inhibitor. '3' toggles the catalytic residues.