C型レクチンドメインをもつ血液凝固因子結合タンパク質の立体構造

概要

論文の詳細を見る
Blood coagulation factors IX/X-binding protein(IX/X-bp)is a heterodimer consisting of two homologous subunits. The amino acid sequence of each subunit is homologous to the carbohydrate-recognition domain of C-type lectin(C-type CRD), although IX/X-bp has no lectin activity. Crystal structure of IX/X-bp shows that a central loop projects into the adjoining subunit and contributes to an intertwinned dimer in a manner similar to 3D domain swapping. The exchange of the loop complete the C-type CRD fold, and forces a large conformational change on the hinge region classically concerned in Ca^<2+> and carbohydrate-binding. This may result in the disruption of the lectin active site. On the other hand, a concave surface created by the dimerization provides a potential binding site for factors IX and X. The domain swapping seen here provides a new function which is not expected from the original C-type CRD.
日本生物物理学会の論文
1998-11-25