CRYSTAL-STRUCTURE OF THE V-ALPHA DOMAIN OF A T-CELL ANTIGEN RECEPTOR
CRYSTAL-STRUCTURE OF THE V-ALPHA DOMAIN OF A T-CELL ANTIGEN RECEPTOR
复制标题
DOI：
10.1126/science.270.5243.1821
复制
发表时间：
1995-12-15
期刊：
影响因子：
56.9
通讯作者：
MARIUZZA, RA
中科院分区：
文献类型：
--
作者：
FIELDS, BA;OBER, B;MARIUZZA, RA
以2.2埃的分辨率测定T细胞抗原受体（TCR）的V-α结构域的晶体结构。该结构代表不同于先前描述的那些的免疫球蛋白拓扑结构集合。多肽链从一个β折叠到另一个折叠的转换使得一对V-alpha同源二聚体能够包装在一起以形成四聚体，使得同源二聚体彼此平行并且所有高变环面向一个方向。基于观察到的V-α结合模式，可以相对于主要组织相容性复合体II类（α β）（2）四聚体定位（α β）（2）TCR四聚体的模型，其中V-α的第三高变环在抗原肽的氨基末端部分上，V-β的相应环在其羧基末端残基上。由α链介导的TCR二聚化可能有助于T细胞活化期间抗原识别与信号转导的偶联。
The crystal structure of the V-alpha domain of a T cell antigen receptor (TCR) was determined at a resolution of 2.2 angstroms. This structure represents an immunoglobulin topology set different from those previously described. A switch in a polypeptide strand from one beta sheet to the other enables a pair of V-alpha homodimers to pack together to form a tetramer, such that the homodimers are parallel to each other and all hypervariable loops face in one direction. On the basis of the observed mode of V-alpha association, a model of an (alpha beta)(2) TCR tetramer can be positioned relative to the major histocompatibility complex class II (alpha beta)(2) tetramer with the third hypervariable loop of V-alpha over the amino-terminal portion of the antigenic peptide and the corresponding loop of V-beta over its carboxyl-terminal residues. TCR dimerization that is mediated by the alpha chain may contribute to the coupling of antigen recognition to signal transduction during T cell activation.