Suter U, Bastos R, Hofstetter H
Department of Biotechnology, Ciba-Geigy Ltd, Basel, Switzerland.
Nucleic Acids Res. 1987 Sep 25;15(18):7295-308. doi: 10.1093/nar/15.18.7295.
Overlapping clones which contain the complete gene encoding the human lymphocyte IgE receptor (MW:45kd; identical with CD23), were isolated from human genomic lambda-libraries. The gene spans approximately 13kb and comprises 11 exons. The 5'-end of the mRNA was mapped by primer extension and S1-mapping, revealing two initiation sites for transcription. Two corresponding TATA boxes were identified by sequencing the 5'-flanking region. A 188bp long inverted repeat was found which flanks the promoter region and could possibly be involved in gene regulation. Exons 9 to 11 code for the IgE-binding domain of the receptor which shows homology to several lectins, particularly to the asialoglycoprotein receptor. A comparison of the exon/intron arrangement of these genes implies that their lectin domains have evolved from a common ancestral cassette.
从人基因组λ文库中分离出了重叠克隆，这些克隆包含编码人淋巴细胞IgE受体（分子量：45kd；与CD23相同）的完整基因。该基因跨度约13kb，由11个外显子组成。通过引物延伸和S1图谱分析确定了mRNA的5'端，揭示了两个转录起始位点。通过对5'侧翼区域进行测序鉴定出了两个相应的TATA框。发现一个188bp长的反向重复序列位于启动子区域两侧，可能参与基因调控。外显子9至11编码受体的IgE结合结构域，该结构域与几种凝集素具有同源性，特别是与去唾液酸糖蛋白受体。对这些基因的外显子/内含子排列进行比较表明，它们的凝集素结构域是从一个共同的祖先盒进化而来的。
