XXXX promoters @entity70742 and @entity9868 . Examples of positive control.

@entity6739 @entity70742 @entity3928 @entity9868 @entity29417 @entity375
Transcription of the two unlinked structural genes @entity70742 and @entity9868 of @entity375 is positively regulated by the gene product @entity29417 . We have used S1 digestion and primer extension mapping to investigate the RNAs produced in different genetic backgrounds: wild-type, @entity29417 deletion mutants, constitutively induced and non-inducible @entity29417 mutants. Results show that each structural gene specifies multiple messenger RNA classes with different 5'-terminal sequences. The basal level of these transcripts does not require a functional @entity29417 gene. Induction of @entity70742 results from an even increase of the level of synthesis of all the transcripts in contrast to that of @entity9868 which is effected by selectively increasing the levels of synthesis of one subset of transcripts. The @entity29417 -mediated control was also studied in the foreign genetic background of @entity6739 using autonomously replicating hybrid plasmids carrying the gene @entity70742 or @entity9868 along with the regulatory gene @entity29417 , either in a constitutive or non-inducible allelic form. The 5' ends of the transcripts @entity70742 and @entity9868 made in @entity6739 map upstream from the initiation sites used in @entity375 . In contrast to @entity375 , in @entity6739 the @entity9868 but not @entity70742 transcripts respond to the @entity29417 -induction. We have identified a minimal control region for the @entity29417 -specific induction of @entity70742 , that includes sequences located between the T-A-T-A box and the translation start codon. This region contains sequence features in common with @entity9868 . There is an extensive alternating Pu:Py region including the T-A-T-A box of both promoters and an eight base-pair exact homology; further downstream, there is another 11 base-pair highly conserved sequence which either @entity3928 or lies in close proximity to the unregulated start sites of @entity70742 in @entity6739 and of @entity9868 in @entity375 . A positive regulatory model taking into accounts all these observations is presented.
