sentences:  Stellacyanin is ubiquitous among vascular seed plants.It is a 20kDa protein whose structure is made up of beta strands forming two beta sheets to form a Greek key beta barrel with variable alpha helical structure.The copper binding domain of the protein is located at the amino-terminal end, while the carboxyl-terminal end is rich in hydroxyproline and serine residues, typical of proteins associated with cell walls of plants.