Ca 2+ and Mg 2+ -ATP binding sites can be found in the coat protein of the wheat mosaic virus. By binding Ca 2+ through an EF-hand, the Coat protein is able to induce the binding of Mg 2+ -ATP, which is necessary to start the serine-threonine kinase activity. The ability of proteins to bind chitin, collagen, or fibrillar cellulose is facilitated by the addition of a coating containing serine kinase activity. When the PPM enzyme domain that binds Mg 2+ -ATP is triggered, glycosyl hydrolases as well as swelling enzymes become active. The expansion of the cell wall can be attributed to the fact that this process requires the hydrolysis of the glycosyl chains found in proteins. After then, the motor domains of the coat protein spin and puncture holes in the cell wall as they move about. In the end, the coat protein inserts viral genetic material into plant cells while simultaneously creating membrane fusion pores on the cell membrane through the use of phospholipid transporter domains.