Legume lectin of view of protein structure. Despite the conserved structure of the legume lectin subunit, they can adopt a wide range of quaternary structures. The reason behind this remarkable variability is probably to be found in the interaction with multivalent ligands. Legume lectin The legume lectins (or L-type lectins) are a family of sugar-binding proteins or lectins found in the seeds and, in smaller amounts, in the roots, stems, leaves and bark of plants belonging to the Fabaceae family. The exact function of the legume lectins "in vivo" is unknown but they are probably involved in the defense of plants against
Collagen helix – this should not be confused with the right-handed alpha helix. These three left-handed helices are twisted together into a right-handed triple helix or "super helix", a cooperative quaternary structure stabilized by many hydrogen bonds. With type I collagen and possibly all fibrillar collagens, if not all collagens, each triple-helix associates into a right-handed super-super-coil referred to as the collagen microfibril. Each microfibril is interdigitated with its neighboring microfibrils to a degree that might suggest they are individually unstable, although within collagen fibrils, they are so well ordered as to be crystalline. A distinctive feature of collagen is the