THIAMINE-REPRESSIBLE GENES IN SCHIZOSACCHAROMYCES-POMBE ARE REGULATEDBY A CYS(6) ZINC-FINGER MOTIF-CONTAINING PROTEIN

Our previous genetic data indicate that the product of the Schizosacch aromyces pombe thi1 gene acts as an activator of several thiamine-repr essible genes which are involved in the control of thiamine metabolism [Schweingruber et al., Genetics 130 (1992) 445-449; Zurlinden and Sch weingruber, Gene 117 (1992) 141-143]. In this communication, we report the cloning and sequencing of thi1 and show that it carries an open r eading frame which translates into a 775-amino-acid protein with the c haracteristics of a Cys(6) zinc-finger-motif-containing transcription factor, as typified by Saccharomyces cerevisae GAL4. We, therefore, su ggest that the thi1-encoded protein binds to upstream activator sequen ces of thiamine-repressible genes.