Fig. 3. Minichromosome constructs. In the center is the unaltered TRP1/ARS1 minichromosome, showing the positions of the nucleosomes and nuclease-hypersensitive sites. The arrow represents the direction of transcription of the TRP1 gene. In the expanded box at the bottom is a blow-up of the ARS1 region of the minichromosome showing the placement of the lac operator. Bases in bold are those shared between the B2 element and the lac operator. Expanded at the top are the STE6 inserts for the four minichromosomes used in this study. All four fragments were cloned into HSR B at the EcoRI site. Gaps in the STE6 insert represent the extent of sequence removed (not drawn to scale). Indicated are the α2 operator, the start site for transcription, and the ARS consensus sequence (ACS) present at the 3′ end of the gene.