1qub

Publication Abstract from PubMed

Human beta(2)-glycoprotein I is a heavily glycosylated five-domain plasma membrane-adhesion protein, which has been implicated in blood coagulation and clearance of apoptotic bodies from the circulation. It is also the key antigen in the autoimmune disease anti-phospholipid syndrome. The crystal structure of beta(2)-glycoprotein I isolated from human plasma reveals an elongated fish-hook-like arrangement of the globular short consensus repeat domains. Half of the C-terminal fifth domain deviates strongly from the standard fold, as observed in domains one to four. This aberrant half forms a specific phospholipid-binding site. A large patch of 14 positively charged residues provides electrostatic interactions with anionic phospholipid headgroups and an exposed membrane-insertion loop yields specificity for lipid layers. The observed spatial arrangement of the five domains suggests a functional partitioning of protein adhesion and membrane adhesion over the N- and C-terminal domains, respectively, separated by glycosylated bridging domains. Coordinates are in the Protein Data Bank (accession No. 1QUB).

Adhesion mechanism of human beta(2)-glycoprotein I to phospholipids based on its crystal structure.,Bouma B, de Groot PG, van den Elsen JM, Ravelli RB, Schouten A, Simmelink MJ, Derksen RH, Kroon J, Gros P EMBO J. 1999 Oct 1;18(19):5166-74. PMID:10508150^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.