The globins are a superfamily of heme-containing globular proteins, involved in binding and/or transporting oxygen.

[3] This 'globin fold' typically consists of eight alpha helices, although some proteins have additional helix extensions at their termini.

The most famous mutation in the globin fold is a change from glutamate to valine in one chain of the hemoglobin molecule.

This mutation creates a "hydrophobic patch" on the protein surface that promotes intermolecular aggregation, the molecular event that gives rise to sickle-cell disease.

Some of them are the phycobiliproteins, the N-terminal domain of two-component regulatory system histidine kinase, RsbR, and RsbN.