1I1A

CRYSTAL STRUCTURE OF THE NEONATAL FC RECEPTOR COMPLEXED WITH A HETERODIMERIC FC

Summary for 1I1A

• Entry DOI: 10.2210/pdb1i1a/pdb
• Related: 1FC1 1i1c 3fru
• Descriptor: NEONATAL FC RECEPTOR A, CYSTEINE, BETA-2-MICROGLOBULIN, ... (11 entities in total)
• Functional Keywords: mhc class i fold, ig constant domains, immune system
• Biological source: Rattus norvegicus (Norway rat); More
• Total number of polymer chains: 4
• Total formula weight: 98951.33

Authors

Martin, W.L.,West Jr., A.P.,Gan, L.,Bjorkman, P.J. (deposition date: 2001-01-31, release date: 2001-02-14, Last modification date: 2024-10-30)

Primary citation

Martin, W.L.,West Jr., A.P.,Gan, L.,Bjorkman, P.J.
Crystal structure at 2.8 A of an FcRn/heterodimeric Fc complex: mechanism of pH-dependent binding.
Mol.Cell, 7:867-877, 2001

PubMed Abstract: The 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.

PubMed: 11336709
DOI: 10.1016/S1097-2765(01)00230-1

Experimental method

X-RAY DIFFRACTION (2.8 Å)