Collagen's structure: why no secondary structure?

Why does Collagen not have a secondary structure? I know it is a fibrous protein, present in connective tissues, and for fibrous proteins, the secondary structure is apparently more important, and consists of mainly alpha helix or beta pleated sheets. So why does this fibrous protein not have a secondary structure?

Thank you.

I thought so as well. Except that our teacher gave a question specifically asking why it has no secondary structure.

Meh, perhaps it was a trick question.

Thanks very much for your help.

Ok, I see what he meant...

Collagen has a quaternary structure since it is made up of 3 polypeptides (3 alpha helicies)...

(Each polypeptide of collagen has secondary structure)

I think that the separate polypeptides are referred to as procollagen rather than collagen. I could be wrong though.

BTW..are you any good at chemistry? If so have a look at my thread in the chemistry subforum I'm stuck!