Binds double-stranded DNA tightly but without sequence specificity. It is distributed uniformly and abundantly on the chromosome, suggesting a role in chromatin architecture. However, it does not significantly compact DNA. Binds rRNA and mRNA in vivo. May play a role in maintaining the structural and functional stability of RNA, and, perhaps, ribosomes. Homotetramer. Acetylated. Deacetylation by the SIR2-homolog deacetylase may regulate its activity. Belongs to the histone-like Alba family.