What do β-turns primarily consist of in protein architecture?

β-turns are specific structural motifs within proteins that facilitate the folding and stability of the overall three-dimensional conformation. They primarily consist of unstructured sequences that allow the polypeptide chain to reverse direction, creating tight loops or bends in the protein structure.

These turns often involve four amino acid residues, and their unstructured nature is crucial for the flexibility and dynamic movement of the protein. This flexibility allows proteins to maintain their functional shapes and to interact appropriately with other molecules.

While peptide bonds connect the amino acids in the protein backbone, it is the flexible, unstructured segments that make up the β-turns specifically. They do not primarily consist of polysaccharide links or hydrophobic residues, although hydrophobic interactions can play a role in the overall protein stability. In this specific context, the unstructured nature of the sequences in β-turns is what defines and characterizes them as functional components in protein architecture.