1i1a
From Proteopedia
CRYSTAL STRUCTURE OF THE NEONATAL FC RECEPTOR COMPLEXED WITH A HETERODIMERIC FC
Structural highlights
FunctionFCGRN_RAT Binds to the Fc region of monomeric immunoglobulins gamma. Mediates the selective uptake of IgG from milk and helps newborn animals to acquire passive immunity. IgG in the milk is bound at the apical surface of the intestinal epithelium. The resultant FcRn-IgG complexes are transcytosed across the intestinal epithelium and IgG is released from FcRn into blood or tissue fluids (By similarity). Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe neonatal Fc receptor (FcRn) transports immunoglobulin G (IgG) across epithelia, binding IgG in acidic vesicles (pH < or = 6.5) and releasing IgG in the blood at pH 7.4. Well-ordered FcRn/Fc crystals are prevented by the formation of "oligomeric ribbons" of FcRn dimers bridged by Fc homodimers, thus we crystallized a 1:1 complex between rat FcRn and a heterodimeric Fc containing only one FcRn binding site. The 2.8 A complex structure demonstrates that FcRn uses its alpha2 and beta2-microglobulin domains and carbohydrate to interact with the Fc C(gamma)2-C(gamma)3 interface. The structure reveals conformational changes in Fc and three titratable salt bridges that confer pH-dependent binding, and can be used to guide rational design of therapeutic IgGs with longer serum half-lives. Crystal structure at 2.8 A of an FcRn/heterodimeric Fc complex: mechanism of pH-dependent binding.,Martin WL, West AP Jr, Gan L, Bjorkman PJ Mol Cell. 2001 Apr;7(4):867-77. PMID:11336709[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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