Pasteurella multocida由来の細菌毒素の細胞内機能領域の構造と機能解析

抄録

Pasteurella multocida toxin (PMT) is one of virulence factors responsible for the pathogenesis in some Pasteurellosis. We determined the crystal structure of the C-terminal region of PMT (C-PMT), which carries an intracellularly active moiety. The overall structure of C-PMT displays three different domains designated C1, C2 and C3. We found in the C3 domain the Cys-His-Asp catalytic triad that is organized only when the Cys is released from a disulfide bond. The steric alignment of the triad corresponded well to that of papain or other enzymes carrying the Cys-His-Asp triad. Our results demonstrate that PMT is an enzymatic toxin carrying the cysteine-protease like catalytic triad, which is organized only under reducing conditions.