Myosin with two FERM domains in the tail region. It has an extended lever arm consisting of five calmodulin binding IQ motifs followed by a single alpha helix (SAH). Myosin VII is required for phagocytosis in "Dictyostelium discoideum", spermatogenesis in "C. elegans" and stereocilia formation in mice and zebrafish. Myosin VIII is a plant-specific myosin linked to cell division; specifically, it is involved in regulating the flow of cytoplasm between cells and in the localization of vesicles to the phragmoplast. Myosin IX is a group of single-headed motor proteins. It was first shown to be minus-end directed, but a later study
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