The SPT4, SPT5, and SPT6 gene products define a class of transcriptional 
repressors in Saccharomyces cerevisiae that are thought to function through 
their effects on chromatin assembly or stability. Mutations in these genes 
confer a similar range of phenotypes to mutations in HIR genes, which encode 
transcriptional repressors that regulate expression of many of the core histone 
genes. Here we show that mutations in the three SPT genes also affect 
transcription of the histone genes that reside at the HTA1-HTB1 locus. HTA1-lacZ 
transcription was reduced in each spt mutant background, an effect that required 
a negative site in the HTA1 promoter. The transcriptional effect could be 
reversed by the overproduction of histones H2A and H2B in an spt4 mutant and 
histones H3 and H4 in all three spt mutants. Suppression of the spt4 
transcriptional defect was dependent on the overproduction of both histones H2A 
and H2B, and required the presence of N-terminal amino acids in both histones. 
The results are consistent with the idea that the effects of the spt mutations 
on nucleosome assembly and/or stability activate repressors of HTA1 
transcription.