Myosin to muscle cells (hence "myo-"(s) + "-in"), there is no single "myosin"; rather it is a very large superfamily of genes whose protein products share the basic properties of actin binding, ATP hydrolysis (ATPase enzyme activity), and force transduction. Virtually all eukaryotic cells contain myosin isoforms. Some isoforms have specialized functions in certain cell types (such as muscle), while other isoforms are ubiquitous. The structure and function of myosin is globally conserved across species, to the extent that rabbit muscle myosin II will bind to actin from an amoeba. Most myosin molecules are composed of a head, neck, and tail
Keratin 6A encoded by separate genes located within the type II keratin gene cluster on human chromosome 12q. It is found with keratin 16 and/or keratin 17 in the palm and sole epidermis, the epithelial cells of the nail bed, the filiform papillae of the tongue, the epithelial lining of oral mucosa and esophagus, as well as the hair follicles. This keratin 6 isoform is thought to be the most abundant of the K6 isoforms. The "KRT6A" gene consists of 9 exons separated by 8 introns and is located in the type II keratin gene cluster on human "chromosome" 12q. Keratin 6B