Sequence analysis of a 62-kb region overlapping the human KLRC cluster of genes

The NKG2 family of genes (HGMW-approved symbol KLRC) contains at least four members (NKG2-A, -C, -E, and -F) which are localized to human chromosome 12p12.3-p13.2. This region, called the natural killer (NK) complex, encodes for lectin-like genes preferentially expressed on NK cells. One of them, the human CD94 gene (HGMW-approved symbol KLRD1), encodes for a protein that has been shown to be covalently associated with the NKG2-A molecule. In this report, we showed that the NKG2 and CD94 genes are localized in a small region (< 350 kb) and we mapped them in the following order: (NKG2-C/NKG2-A)/NKG2-E/NKG2-F/NKG2-D/CD 94. Sequence analysis of 62 kb spanning the NKG2-A, -E, -F, and -D loci allowed the identification of two LINE elements that could have been involved in the duplication of the NKG2 genes. Presence of one MIR and one L1ME2 element at homologous positions in the NKG2-A and NKG2-F genes is consistent with the existence of rodent NKG2 gene(s). Finally, we mapped the 5'-ends of the NKG2-A transcripts into two separate regions showing the existence of two separate transcriptional control regions upstream of the NKG2-A locus and defining putative promoter elements for these genes.