Are you all talking about the same type of structure?
If you want the tertiary structure (3D) there is no such thing, as DK
pointed out.
If you want the secondary structure, protein prediction servers might
get you started as Dr Buxbaum pointed out.
If you have no idea what kind of protein you have, a mass spectrometer
can help to identify it.
(If you have no idea what the difference between primary, secondary and
tertiary structure is, go read a textbook on biochemistry).
Sander
