Taketani S, Inazawa J, Abe T, Furukawa T, Kohno H, Tokunaga R, Nishimura K, Inokuchi H
Department of Hygiene, Kansai Medical University, Osaka, Japan.
Genomics. 1995 Oct 10;29(3):698-703. doi: 10.1006/geno.1995.9949.
We determined the structure of the human protoporphyrinogen oxidase (PPOX) gene after isolation and characterization of lambda phage clones mapping discrete regions of the cDNA. Southern blotting of human genomic DNA showed that there is a single copy of the PPOX gene, and fluorescence in situ hybridization to metaphase chromosomes mapped the gene to region 1q22. The gene has 13 exons and about 8 kb. The exon/intron boundary sequences conform to consensus acceptor (GTn) and donor (nAG) sequences, and exons in the gene appear to encode functional protein domains. Primer extension analysis revealed two major transcriptional initiation sites in a region with sequence motifs characteristic of a promoter. The promoter region contains multiple Sp1 elements, CCAAT boxes, and potential GATA-1 binding sites. Mapping of the 5' end PPOX mRNA by polymerase chain reaction indicated that there are the same transcripts in erythroid and nonerythroid cells.
在分离并鉴定了定位cDNA离散区域的λ噬菌体克隆后，我们确定了人类原卟啉原氧化酶（PPOX）基因的结构。对人类基因组DNA进行的Southern印迹分析表明，PPOX基因有单拷贝，与中期染色体进行的荧光原位杂交将该基因定位到1q22区域。该基因有13个外显子，约8 kb。外显子/内含子边界序列符合共有受体（GTn）和供体（nAG）序列，并且该基因中的外显子似乎编码功能性蛋白质结构域。引物延伸分析在具有启动子特征性序列基序的区域中揭示了两个主要转录起始位点。启动子区域包含多个Sp1元件、CCAAT框和潜在的GATA-1结合位点。通过聚合酶链反应对PPOX mRNA的5'端进行定位表明，在红细胞和非红细胞中存在相同的转录本。
