The application Cn3D will open enabling you to see the structure of your protein. You can rotate the 3-D structure by dragging it with your mouse. The catalytic active region is shown in red.
The color key matches the amino acid sequence information in the window that appears below the 3-D representation of your protein:
Change the display format of Cn3D by selecting Style –> Rendering Shortcuts –> Worms:
Now you should be able to rotate the structure to clearly see the α/β barrel site in the center.