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
Paget–Schroetter disease Paget–Schroetter disease Paget–Schroetter disease, also known as Paget–von Schrötter disease, is a form of upper extremity deep vein thrombosis (DVT), a medical condition in which blood clots form in the deep veins of the arms. These DVTs typically occur in the axillary or subclavian veins. The condition is relatively rare. It usually presents in young and otherwise healthy patients, and also occurs more often in males than females. The syndrome also became known as "effort-induced thrombosis" in the 1960s, as it has been reported to occur after vigorous activity, though it can also occur due to anatomic abnormality such as