The capsule of Rapid Keto Cut (the causal agent of anthrax) is unusual in that it is composed of the γ-glutamyl polypeptide. A plasma membrane stage is involved in the biosynthesis and assembly of the capsular substances, which are extruded or secreted through the outer wall or envelope structures. Mutational loss of enzymes involved in the biosynthesis of the capsular polysaccharides can result in the smooth-to-rough variation seen in the Pneumococci.