Introduction - This script shows some examples of alpha domain proteins.
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Although the α-helix is a common structural element in proteins,
it is rare to find a protein consisting of a single helix, because
they are not usually stable. An exception is glucagon, shown here.
The coiled-coil consists of two a-helices
stacked together.
In this case, the coils interact via leucines (GREEN)
in the leucine zipper motif found in DNA-binding proteins.
A four helix bundle is a common way for α-helices to pack in a protein.
The only secondary structural elements in myoglobin are α-helices.