[1] [2]
Function
Cellulose synthase has two main jobs. The first of these two being the synthesis or creation of the polysaccharide cellulose [3] and the second job of cellulose synthase is to create the crystalline microfibril structure [4]. Cellulose synthase uses an activated form of glucose, with the sugar attached to a nucleotide, to build cellulose. Cellulose is one of the main components in the cell wall and is responsible for protecting the cell from unwarranted pathogens that might try and harm the cell [5]. Cellulose is also important in strengthening cell walls and preventing breakage due to physical forces. The overall shape and form of the cell, as well as the containment of water within the cell.
Relevance
Why is cellulose synthase so important? Cellulose synthase is an enzyme that helps form the structure of cellulose. Cellulose is a polymer that is composed of many other homopolymers [6]. Cellulose has many important jobs within a cell that without cellulose the cell could not function. Things like the formation of the cell wall which is vital to the life of a plant cell are all dependent on the synthesis of cellulose [7]. Cellulose is water insoluble because of the inter and intra hydrogen bonding that occurs within the cell, this is relevant because cellulose is constantly in contact with water within the cell. The constant synthesis of cellulose is imperative to the survival of the cell.
Structural highlights
The primary structure of cellulose sythase is a long chain of glucose units [8]. It is attached through Beta(1,4) linkages which appear to be like a sheet making up the structures secondary structure of the protein. [9]. These features can all be seen in the rotating figure above.
Beta linkages form , 6 stranded beta sheets to be exact along with the beta sheets there can be found the 5 . These chains form hydrogen bonds with each other forming microfibrils helping to create the overall strength and stability of cellulose [10]. Though much research has been done, the tertiary and quinary structure of cellulose synthase has been difficult to find because of complications with things like purification of the active enzyme, and the overall difficulty of crystalizing plant cellulose synthase. In the 3D model that we have displayed is that of a bacterial cellulose synthase. With the use of of technology and what we know about bacterial cellulose synthase there have been projected images of the tertiary and quaternary structure. The bacterial cellulose synthase is similar to a plants cellulose synthase in that the cell membrane, using -glucose from the cytoplasm, passing through the cell membrane, and extruding outside the cell.
