Occurrence of a single helix of the collagen type in globular proteins.

The occurrence of an eight-residue long segment of polypeptide chain in collagen helical conformation has been detected in bacteriochlorophyll a-protein by the application of an algorithm for identifying secondary structures in globular proteins from their alpha-carbon positions. This segment spans residues 277 to 284 of the protein and is the longest known stretch of collagen helix to be observed in globular proteins.