GLYCOSYLATION OF RNA-POLYMERASE-II FROM WHEAT-GERM

RNA polymerase II from wheat germ was analyzed for the presence of sug ars, The two largest subunits and the 27 and 25 kDa subunits mere foun d to be glycosylated by a variety of sugars, However, no N-acetylgluco samine was detected, which was found by Kelly et al, (J, Biol, Chem, ( 1993) 268, 10416-10424) in the largest subunit of RNA polymerase II fr om calf thymus, Thus it appears that the regulatory function of this s ugar, postulated by Kelly et al., is performed in the wheat germ enzym e by other monosaccharides, Carbohydrate analysis of the two largest s ubunits of the calf thymus enzyme also revealed the presence, beside N -acetylglucosamine, of other sugars, Some similarities in the features of glycosylation of the two polymerases, isolated from very different organisms, suggest that the sugar moieties have an important role in the structure and/or function of these enzymes. (C) 1997 Federation of European Biochemical Societies.