THE TBP GENE FROM ASPERGILLUS-NIDULANS - STRUCTURE AND EXPRESSION IN SACCHAROMYCES-CEREVISIAE

The genomic and cDNA copy of the TATA-binding protein (TBP) gene from the filamentous fungus Aspergillus nidulans have been cloned. The gene is interrupted by four introns, one of which is in the long 5' untran slated region of 615 bp. The transcription initiation site was establi shed and the levels of mRNA were analysed under diverse growth conditi ons and found to vary severalfold. The gene encodes a protein of 268 a mino acids composed of an N-terminal domain of 88 amino acids with no significant homology to other TBPs and a C-terminal domain of 180 amin o acids with about 95% homology to other fungal TBPs. A cDNA clone und er the yeast ADH1 promoter was able to substitute for the yeast TBP ge ne in vivo; however, the transformants obtained grew poorly at 35 degr ees C and on galactose and glycerol at 30 degrees C, though they could grow in the presence of copper ions or aminotriazole at this temperat ure. This phenotype may be the result of altered function of A. nidula ns TBP in certain yeast transcription activation pathways.