In virtually all eukaryotic organisms, linker DNA between nucleosomes is 
associated with a histone termed linker histone or histone H1. In Saccharomyces 
cerevisiae, HHO1 encodes a putative linker histone with very significant 
homology to histone H1. The encoded protein is expressed in the nucleus, but has 
not been shown to affect global chromatin structure, nor has its deletion shown 
any detectable phenotype. In vitro chromatin assembly experiments with 
recombinant HHO1p have shown that it is able to complex with dinuncleosomes in a 
similar manner to histone H1. Here we report that while disruption of HHO1 has 
little affect on RNA levels of most cellular transcripts, there are numerous 
exceptions. Measurement of HHO1p concentration in the wild-type cell showed a 
stoichiometry of about one HHO1p molecule per 37 nucleosomes. Localization of 
HHO1p in the chromatin, using an immunoprecipitation technique, showed 
preferential HHO1p binding to rDNA sequences. These results suggest that HHO1p 
may play a similar role to linker histones, but at restricted locations in the 
chromatin.