Globinfolds

Globinfolds refers to a family of protein structures characterized by a common three-dimensional fold. This fold is primarily composed of alpha-helices and is found in a wide variety of proteins, most notably the globins. Globins are a superfamily of proteins that include hemoglobin, myoglobin, and neuroglobins. Hemoglobin, found in red blood cells, is responsible for oxygen transport, while myoglobin, located in muscle tissue, stores oxygen. Neuroglobins are found in the brain and may play a role in oxygen homeostasis or protection.

The characteristic globin fold consists of eight alpha-helices arranged in a compact, globular structure. These helices are typically labeled alphabetically from A to H, and their arrangement creates a hydrophobic pocket. This pocket is crucial for the binding of a heme group, an iron-containing porphyrin ring. The iron atom within the heme group is the site of oxygen binding, allowing globins to perform their physiological functions. The precise arrangement and interactions of the helices, along with surrounding residues, determine the specific properties and binding affinities of different globin proteins. The globinfold is considered a highly conserved structural motif, indicating its evolutionary importance and functional significance. Variations within the globinfold allow for diverse roles beyond oxygen transport, including signaling and gene regulation in some members of this superfamily.