A search for the occurrence of the rare π-helix
was performed with Iditis from the Oxford Molecular Group
upon the Protein Data Bank. In 8 of the 10 confirmed crystal
structures that harbor the π-helix, its unique conformation
has been linked directly to the formation or stabilization
of a specific binding site within the protein. In the discussion
to follow, the role for each of these eight π-helices
will be addressed in regard to protein function. It is
clear upon closer examination that the conformation of
the π-helix has evolved to provide unique structural
features within a variety of proteins.