Phosphofructokinase enzyme , molecular model. This enzyme is from the spirochaete bacteria Borrelia burgdorferi, which causes Lyme disease. The enzyme is involved in regulating the process of releasing energy from glucose. The bacteria, called spirochaetes because of their helical form, are transmitted by ticks and cause Lyme disease. This disease has many symptoms including rashes and arthritis. In this model, solid colours represent the secondary structure of the protein (spiral ribbons are alpha helices; arrows are beta sheets), and the faded tubular structure behind represents the individual atoms and bonds.