Binds double-stranded DNA tightly but without sequence specificity. It is distributed uniformly and abundantly on the chromosome, suggesting a role in chromatin architecture. Binds rRNA and mRNA in vivo. May play a role in maintaining the structural and functional stability of RNA, and, perhaps, ribosomes (By similarity). Incubation with DNA in vitro gives fibrous structures 10.3 +/- 1.1 nm in thickness (naked DNA is 1.83 +/- 0.37 nm). This protein does not significantly compact DNA (PubMed:21148291). Homotetramer. Acetylated. Deacetylation by the SIR2-homolog deacetylase may regulate its activity. Belongs to the histone-like Alba family.