[Role of serine-rich histone (H5) in bird erythrocyte genome inactivation].

The ability of H5 and H1 histones, purified from immature or mature pigeon erythroid cells, to suppress RNA synthesis in vitro was compared. It was found that H1 histones from both sources as well as histone H5 from bone marrow suppress RNA synthesis to a comparable degree while H5 from the mature erythrocytes exhibits significantly higher suppression efficiency. H5 histone subfractions, differing in phosphate content, also had different ability to restrict the template activity of chromatin: the higher is the phosphorylation level of H5 histone, the weaker is its effect on the transcription.