The Structure of the Tessera; the Unit Structure of Murein Wall

Abstract

To enclose the surface area of a bacterium, a very large number of the penta-muropeptides have to be covalently linked together. This fabric can either be considered to be a network or as a porous material containing a large number of pores. The smallest functional unit of surface around a pore, delimited by a ring of covalently linked atoms, is called a tessera. The covalent structure of the tessera has a rigid, strong structure resulting from its formation from ten disaccharide penta-muropeptides. There are two muropeptide pairs linked to each other to form two nona-muropeptides, two muropeptides point above the surface plane, two of them point below, and two point outward within the plane and are part of other tesserae.