Structure Killer-cell immunoglobulin-like receptor

1 structure

1.1 gene structure

1.1.1 genes


1.2 protein structure

structure
gene structure

the kir gene cluster has approximately 150 kb , located in leukocyte receptor complex (lrc) on human chromosome 19q13.4. kir genes have 9 exons, correlated kir receptor protein domains (leader, d0, d1, , d2, stem, transmembrane, , cytosolic domains). furthermore, promoter regions of kir genes share greater 90% sequence identity, indicates there similar transcriptional regulation of kir genes.

the human killer cell immunoglobulin-like receptors superfamily (which share 35-50% sequence identity , same fold kir) includes immunoglobulin-like transcripts (ilt, known leukocyte immunoglobulin-like receptors (lirs)), leukocyte-associated ig-like receptors (lair), paired ig-like receptors (pir), , gp49. moreover, has been reported between 12 , 17 kir receptors have been identified. there single ancestral gene extant kir receptor genes arose via duplications, recombinations, , mutations, , kir receptors share more 90% sequence identity.

genes

two domains, long cytoplasmic tail: kir2dl1, kir2dl2, kir2dl3, kir2dl4, kir2dl5a, kir2dl5b,
two domains, short cytoplasmic tail: kir2ds1, kir2ds2, kir2ds3, kir2ds4, kir2ds5
three domains, long cytoplasmic tail: kir3dl1, kir3dl2, kir3dl3
three domains, short cytoplasmic tail: kir3ds1

protein structure

nk cell receptors bind directly mhc class molecules on surface of target cells. human killer cell immunoglobulin-like receptors recognize α1 , α2 domains of class human leukocyte antigens (hla-a, -b, , –c), human versions of mhcs. position 44 in d1 domain of kir receptors , position 80 in hla-c important specificity of kir-hla binding.