Maeng J H, Yoon J B
Department of Biochemistry, College of Science, Yonsei University, Seoul, 120-749, Korea.
J Biochem. 1998 Jul;124(1):23-7. doi: 10.1093/oxfordjournals.jbchem.a022085.
PTF/SNAPc is a multisubunit complex which specifically recognizes the PSEs of small nuclear RNA genes and activates transcription by RNA polymerase II or III. Here we describe the isolation and characterization of genomic clones encoding the human PTFgamma/SNAP43 gene. The gene spans approximately 29 kilobases, and is composed of 9 exons and 8 introns. A major transcription initiation site was identified at the position 58 base pairs upstream of the AUG translation initiator codon on primer extension analysis with HeLa mRNA. The 5' flanking region lacks a typical TATA box but contains many putative binding sites for various transcription factors, such as Sp1, Oct1, NF1, AP1, E2F, and USF. Immediately downstream of the transcription start site, we found a VNTR of a 17-bp sequence rich in (G+C). Four different alleles with two to five copies of the tandem repeat were identified in 10 individuals examined, indicating a high degree of variation at the PTFgamma/SNAP43 locus. In addition, the PTFgamma/SNAP43 gene was mapped to human chromosome 14q22 by fluorescence in situ hybridization.
PTF/SNAPc是一种多亚基复合物，它能特异性识别小核RNA基因的近端序列元件（PSEs），并激活RNA聚合酶II或III的转录。在此，我们描述了编码人类PTFγ/SNAP43基因的基因组克隆的分离和特性。该基因跨度约29千碱基，由9个外显子和8个内含子组成。在用HeLa mRNA进行引物延伸分析时，在AUG翻译起始密码子上游58个碱基对处确定了一个主要转录起始位点。5'侧翼区域缺乏典型的TATA盒，但含有许多各种转录因子的假定结合位点，如Sp1、Oct1、NF1、AP1、E2F和USF。在转录起始位点的紧邻下游，我们发现了一个富含（G+C）的17碱基序列的可变数目串联重复序列（VNTR）。在检测的10个个体中鉴定出了具有两到五个串联重复拷贝的四种不同等位基因，表明PTFγ/SNAP43基因座存在高度变异。此外，通过荧光原位杂交将PTFγ/SNAP43基因定位到人类染色体14q22。
