Pertussis toxin they are formed from two subunits. The "A" subunit possesses enzyme activity, and is transferred to the host cell following a conformational change in the membrane-bound transport "B" subunit. Pertussis toxin is an exotoxin with six subunits (named "S1" through "S5"—each complex contains two copies of "S4"). The subunits are arranged in "A-B" structure: the "A" component is enzymatically active and is formed from the S1 subunit, while the "B" component is the receptor-binding portion and is made up of subunits S2–S5. The subunits are encoded by "ptx" genes encoded on a large PT operon that also includes additional genes
Blount's disease Blount's disease Blount's disease is a growth disorder of the tibia (shin bone) that causes the lower leg to angle inward, resembling a bowleg. It is also known as "tibia vara". It is named after Walter Putnam Blount (1900–1992), an American pediatric orthopedic surgeon. It has also been known as Mau-Nilsonne Syndrome, after C. Mau and H. Nilsonne, who published early case reports of the condition. Bowing of one or both legs that may: Failure to treat Blount's disease may lead to progressive deformity.Blount's disease may come back after surgery, especially in younger children. Because of the bowing, a leg-length