The human PTFγ/SNAP43 gene: Structure, chromosomal location, and identification of a VNTR in 5'-UTR

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 PTFγ/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 PTFγ/SNAP43 locus. In addition, the PTFγ/SNAP43 gene was mapped to human chromosome 14q22 by fluorescence in situ hybridization.