Is Protein Structure Handedness Consistent?

[luckymango]

Proteins

Are protein structures always right-handed??

 

[GCT]

Are protein structures always right-handed??

The natural ones are

 

[luckymango]

So does that mean that there won't be any left-handed proteins in our bodies?

 

[GCT]

No, there shouldn't

 

[luckymango]

I'm a bit confused about the right-handed and left-handed proteins. I know that the coiled coil structure has to be left-handed but why wikipedia shows 2 right-handed coil instead?? Does it mean that a the 2 alpha-helix are right-handed but coiled together in a left-handed way??

I have attached a file of what I think a right-handed and left-handed should be.

Below is the url for wikipedia:
http://en.wikipedia.org/wiki/Coiled_coil

 

[GCT]

I'm really not quite sure what you're asking here, the attached file shows a left handed helix on the left and a right handed one on the right.