Functional relationship among TATA sequences, gene induction and transcription initiation in the beta-galactosidase, LAC4, gene from Kluyveromyces lactis.
In the 5' non-coding region of the beta-galactosidase, LAC4, gene of Kluyveromyces lactis, three TATA-like sequences are present at -230, -170 and -142 from the ATG translation start site. By means of deletion mutations in the TATA region, at least two of these TATA sequences, those at -230 and -142, were shown to be required for normal gene expression. Evidence is presented for a functional hierarchy and cooperation between these TATA sequences. The deletion or a change in the position of the TATA sequences affects both beta-galactosidase induction and the location of RNA initiation sites. The TATA sequence at -230 alone is sufficient for correct gene induction when it is moved to a position 41 bp from the major RNA initiation sites located around -110; the -142 TATA alone contributes only partly to gene induction. We suggest a functional distinction between these two related regulatory sequences. This functional distinction might be established by sequence differences and/or targets of unlike specific DNA binding protein(s). A conformational analysis of the LAC4 promoter showed that under torsional stress the functional elements UAS, TATA boxes RNA initiation sites and ATG can be detected as P1-sensitive sites. Possible functions of DNA structural alterations on gene expression are discussed.
Ficca
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AG
Institut für Mikerobiologie, Universität Düsseldorf, Federal Republic of Germany.
Hollenberg
C P
CP
D002872:Chromosome Deletion; D003001:Cloning, Molecular; D004270:DNA, Circular / Q000378:metabolism; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004720:Endonucleases; D005696:Galactosidases / Q000235:genetics*; D005800:Genes, Fungal; D007716:Kluyveromyces / Q000201:enzymology / Q000235:genetics*; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D004718:Saccharomycetales / Q000235:genetics*; D015719:Single-Strand Specific DNA and RNA Endonucleases; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000235:genetics*
D004270:DNA, Circular; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D012319:RNA Polymerase II; D004720:Endonucleases; D015719:Single-Strand Specific DNA and RNA Endonucleases; D005696:Galactosidases; D001616:beta-Galactosidase