Crystal structures of the two membrane-proximal Ig-like domains(D3D4)of LILRB1/B2:alternative models for their involvement in peptide-HLA binding  

作　　者：Gol Nam Yi Shi Myongchol Ryu Qihui Wang Hao Song Jun Liu Jinghua Yan Jianxun Qi George F Gao 

机构地区：[1]CAS Key Laboratory of Pathogenic Microbiology and Immunology,Institute of Microbiology,Chinese Academy of Sciences,Beijing 100101,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Institute of Microbiology,State Academy of Sciences,Pyongyang,Democratic People’s Republic of Korea [4]Research Network of Immunity and Health(RNIH),Beijing Institutes of Life Science,Chinese Academy of Sciences,Beijing 100101,China

出　　处：《Protein & Cell》2013年第10期761-770,共10页蛋白质与细胞（英文版）

基　　金：the China National Grand S&T Spe-cial Project(No.2012ZX10001006);the National Natural Science Foundation of China(Grant No.31030030);GFG is a leading principal investigator of the NSFC Innovative Research Group(Grant No.81021003).

摘　　要：Leukocyte immunoglobulin-like receptors(LILRs),also called CD85s,ILTs,or LIRs,are important mediators of immune activation and tolerance that contain tandem immunoglobulin(Ig)-like folds.There are 11(in addition to two pseudogenes)LILRs in total,two with two Ig-like domains(D1D2)and the remaining nine with four Ig-like domains(D1D2D3D4).Thus far,the structural features of the D1D2 domains of LILR proteins are well defi ned,but no structures for the D3D4 domains have been reported.This is a very important fi eld to be studied as it relates to the unknown functions of the D3D4 domains,as well as their relative orientation to the D1D2 domains on the cell surface.Here,we report the crystal structures of the D3D4 domains of both LILRB1 and LILRB2.The two Ig-like domains of both LILRB1-D3D4 and LILRB2-D3D4 are arranged at an acute angle(~60°)to form a bent struc-ture,resembling the structures of natural killer inhibitory receptors.Based on these two D3D4 domain structures and previously reported D1D2/HLA I complex structures,two alternative models of full-length(four Ig-like domains)LILR molecules bound to HLA I are proposed.

关 键 词：LILRs D3D4 HLA binding crystal structure 

分 类 号：O17[理学—数学]