期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2009
卷号：106
期号：46
页码：19274-19279
DOI：10.1073/pnas.0909755106
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：ADAMTS13 specifically cleaves plasma von Willebrand factor (VWF) and thereby controls VWF-mediated platelet thrombus formation. Severe deficiencies in ADAMTS13 can cause life-threatening thrombotic thrombocytopenic purpura. Here, we determined 2 crystal structures of ADAMTS13-DTCS (residues 287-685), an exosite-containing human ADAMTS13 fragment, at 2.6-A and 2.8-A resolution. The structures revealed folding similarities between the disintegrin-like (D) domain and the N-terminal portion of the cysteine-rich domain (designated the CA domain). The spacer (S) domain forms a globular functional unit with a 10-stranded {beta}-sandwich fold that has multiple interaction sites with the CA domain. We expressed 25 structure-based mutants of ADAMTS13-MDTCS (residues 75-685) and measured their enzymatic activity. We identified 3 VWF-binding exosites on the linearly aligned discontinuous surfaces of the D, CA, and S domains traversing the W-shaped molecule. Since the MDTCS domains are conserved among ADAMTS family proteins, the structural framework of the multiple enzyme-substrate interactions identified in the ADAMTS13-VWF system provides the basis for a common substrate recognition mode in this class of proteinases.
关键词：hemostasis ; metalloproteinase ; modular protein ; substrate recognition
