Ino80 is an ATP-dependent nucleosome-remodeling enzyme involved in 
transcription, replication, and the DNA damage response. Here, we characterize 
the fission yeast Ino80 and find that it is essential for cell viability. We 
show that the Ino80 complex from fission yeast mediates ATP-dependent nucleosome 
remodeling in vitro. The purification of the Ino80-associated complex identified 
a highly conserved complex and the presence of a novel zinc finger protein with 
similarities to the mammalian transcriptional regulator Yin Yang 1 (YY1) and 
other members of the GLI-Krüppel family of proteins. Deletion of this Iec1 
protein or the Ino80 complex subunit arp8, ies6, or ies2 causes defects in DNA 
damage repair, the response to replication stress, and nucleotide metabolism. We 
show that Iec1 is important for the correct expression of genes involved in 
nucleotide metabolism, including the ribonucleotide reductase subunit cdc22 and 
phosphate- and adenine-responsive genes. We find that Ino80 is recruited to a 
large number of promoter regions on phosphate starvation, including those of 
phosphate- and adenine-responsive genes that depend on Iec1 for correct 
expression. Iec1 is required for the binding of Ino80 to target genes and 
subsequent histone loss at the promoter and throughout the body of these genes 
on phosphate starvation. This suggests that the Iec1-Ino80 complex promotes 
transcription through nucleosome eviction.