1nt0

Publication Abstract from PubMed

Serum mannose-binding proteins (MBPs) are C-type lectins that recognize cell surface carbohydrate structures on pathogens, and trigger killing of these targets by activating the complement pathway. MBPs circulate as a complex with MBP-associated serine proteases (MASPs), which become activated upon engagement of a target cell surface. The minimal functional unit for complement activation is a MASP homodimer bound to two MBP trimeric subunits. MASPs have a modular structure consisting of an N-terminal CUB domain, a Ca(2+)-binding EGF-like domain, a second CUB domain, two complement control protein modules and a C-terminal serine protease domain. The CUB1-EGF-CUB2 region mediates homodimerization and binding to MBP. The crystal structure of the MASP-2 CUB1-EGF-CUB2 dimer reveals an elongated structure with a prominent concave surface that is proposed to be the MBP-binding site. A model of the full six-domain structure and its interaction with MBPs suggests mechanisms by which binding to a target cell transmits conformational changes from MBP to MASP that allow activation of its protease activity.

Crystal structure of the CUB1-EGF-CUB2 region of mannose-binding protein associated serine protease-2.,Feinberg H, Uitdehaag JC, Davies JM, Wallis R, Drickamer K, Weis WI EMBO J. 2003 May 15;22(10):2348-59. PMID:12743029^[1]

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