TRANSCRIPTION OF HUMAN 5S-RIBOSOMAL-RNA GENES IS INFLUENCED BY AN UPSTREAM DNA-SEQUENCE

Six human 5S rRNA genes and gene variants and one pseudogene have been sequenced. The six genes/variants were transcribed in a HeLa cell ext ract with about equal efficiency. Three genes contain the Sp1 binding sequence GGGCGG in position -43 to -38 and three genes contain the Sp1 like sequence GGGCCG in this position. The six genes contain furtherm ore one Spl binding site in a position about -245 and one ATF recognit ion site in a position about -202. A 12 bp sequence (GGCTCTTGGGGC) fou nd in position -32 to -21 strongly influenced the transcriptional effi ciency in vitro. This 12-mer, designated the D box, has also been foun d upstream a 5S rRNA gene from hamster and mouse. Removal of the Sp1 b inding sites had no effect on the transcription in vitro whereas the t ranscriptional efficiency decreased to 10% if the D box was removed fr om the human 5S rRNA gene.