The Alu family repeat promoter has a tRNA-like bipartite structure

The essential sequences needed for Alu repeat transcription by RNA polymerase III were mapped. Experimental evidence is presented showing that the Alu repeat promoters are organised in a bipartite structure similar to the split tRNA promoters as suggested by DNA sequence homology. Furthermore, by combining fragments from efficiently and inefficiently transcribed natural Alu repeats in several recombinant clones, it was possible to investigate the regions responsible for their differences. It is clear that, apart from the short stretches of homology with the tRNA consensus sequence, there is very little constraint in the promoter sequences. However, our studies indicate that some influence on the efficiency of transcription may be exerted by regions outside the accepted promoter components.