To define DNA elements involved in thiamine-regulated transcription of the Schizosaccharomyces pombe gene nmt1 (thi3), we analyzed several nmt1 promoter constructs. We detected a DNA element which is required for promoter activation in the absence of thiamine. It is located 54 to 62 bp upstream of the TATA box and matches the consensus sequence of the binding site for the mammalian transcription factor C/EBP (CAAT/enhancer binding protein). We show that the element specifically binds proteins.