Glycosylation, ADP-ribosylation, and methylation of Tetrahymena histones

Abstract

Some of the postsynthetic modifications that occur in macronuclear histones from T. thermophila were examined. When purified macronuclei are incubated with [32P]NAD+, histones H1, H2A, H2B and H3 are ADP-ribosylated. Histones H1, H2A, H2B and H3 contain fucose and mannose residues as evidenced by the incorporation of [3H]fucose and by the specific binding to these proteins of gorse seed lectin and concanavalin A. Finally, studies on incorporation of methyl groups into histones show that histone H2A, together with the related nonhistone protein A24, is methylated in Tetrahymena.