BAS1 has a Myb motif and activates HIS4 transcription only in combination with BAS2.

@article{TiceBaldwin1989BAS1HA,
  title={BAS1 has a Myb motif and activates HIS4 transcription only in combination with BAS2.},
  author={K Tice-Baldwin and Gerald Fink and Kim T. Arndt},
  journal={Science},
  year={1989},
  volume={246 4932},
  pages={931-5}
}
The BAS1 and BAS2 proteins are both required for activation of GCN4-independent (basal) HIS4 transcription in yeast. BAS1 has an NH2-terminal region similar to those of the myb proto-oncogene family. BAS1 and BAS2, which contains a homeo box, bound to adjacent sites on the HIS4 promoter. The joint requirement of BAS1 and BAS2 for activation is probably not due to cooperative binding or the transcriptional control of one of the genes by the other. Although BAS1 and BAS2 were both required for… CONTINUE READING