Identification and analysis of Mot3, a zinc finger protein that binds to the retrotransposon Ty long terminal repeat (delta) in Saccharomyces cerevisiae.
Spt3 and Mot1 are two transcription factors of Saccharomyces cerevisiae that are thought to act in a related fashion to control the function of TATA-binding protein (TBP). Current models suggest that while Spt3 and Mot1 do not directly interact, they do function in a related fashion to stabilize the TBP-TATA interaction at particular promoters. Consistent with this model, certain combinations of spt3 and mot1 mutations are inviable. To identify additional proteins related to Spt3 and Mot1 functions, we screened for high-copy-number suppressors of the mot1 spt3 inviability. This screen identified a previously unstudied gene, MOT3, that encodes a zinc finger protein. We show that Mot3 binds in vitro to three sites within the retrotransposon Ty long terminal repeat (delta) sequence. One of these sites is immediately 5' of the delta TATA region. Although a mot3 null mutation causes no strong phenotypes, it does cause some mild phenotypes, including a very modest increase in Ty mRNA levels, partial suppression of transcriptional defects caused by a mot1 mutation, and partial suppression of an spt3 mutation. These results, in conjunction with those of an independent study of Mot3 (A. Grishin, M. Rothenberg, M. A. Downs, and K. J. Blumer, Genetics, in press), suggest that this protein plays a varied role in gene expression that may be largely redundant with other factors.
Madison
J M
JM
Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.
Dudley
A M
AM
Winston
F
F
D000251:Adenosine Triphosphatases; D000595:Amino Acid Sequence; D001483:Base Sequence; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D004251:DNA Transposable Elements; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D017433:Protein Structure, Secondary; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D016385:TATA Box / Q000235:genetics; D035381:TATA-Binding Protein Associated Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D016335:Zinc Fingers
D004251:DNA Transposable Elements; D005656:Fungal Proteins; C112006:MOT3 protein, S cerevisiae; C075582:SPT3 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D035381:TATA-Binding Protein Associated Factors; D014157:Transcription Factors; D000251:Adenosine Triphosphatases; C073676:MOT1 protein, S cerevisiae; D004265:DNA Helicases