Abstract
The RNA polymerase III transcription complex from Bombyx mori silkworms, in contrast to that from Xenopus frogs, requires a signal that is upstream from the transcription initiation site. Part of the normal 5'' flanking sequence is essential for transcription of Bombyx 5S RNA genes be homologous cell-free extracts. The critical region is structurally similar to the upstream signal that directs Bombyx tRNA gene transcription. The association of such a control element with 2 classes of polymerase III templates argues that it acts through a general component of the Bombyx transcription apparatus.