System comprises four plasma proteins, circulating as zymogens in the bloodstream or being assembled on various cell types: the serine proteases factor XII (FXII), factor XI (FXI), and prekallikrein (PKK) and the nonenzymatic cofactor high-molecularweight kininogen (HK). The latter forms equimolar complexes with plasma kallikrein (PK) or FXI. The cascade is initiated upon contact to a negatively c
R protein. CopB2 is also secreted via a T3S mechanism when ectopically expressed in Yersinia (14), and expression studies have shown that copB2 is a midcycle gene (5). These observations have led to the hypothesis that CopB and CopB2 serve as alternative translocator proteins that could mediate translocation of effector proteins across the chlamydial inclusion membrane at different stages of devel
R protein. CopB2 is also secreted via a T3S mechanism when ectopically expressed in Yersinia (14), and expression studies have shown that copB2 is a midcycle gene (5). These observations have led to the hypothesis that CopB and CopB2 serve as alternative translocator proteins that could mediate translocation of effector proteins across the chlamydial inclusion membrane at different stages of devel