The incubation of disrupted Escherichia coli with 8 mM UDP-[14C]glucose in the presence of Mn++ resulted in the incorporation of [14C]glucose into trichloroacetic acid insoluble reaction product (RP), non extractable by chloroform-methanol (C-M) and C-M-H2O mixtures. The autoradiogram of the RP subjected to SDS-PAGE showed two contiguous bans of low rM, the slower moving one showing a complete dependence on Mn++. Labeled ADPG did not replace UDPG. About two third of both, RP and the acceptor-transferase couple, were recovered in the pellet after centrifugation at 16,000 xg. The glucosylation reaction was reduced about five fold when E. coli was cultured in a medium containing glucose. Neither chase of the incorporated [14C]glucose nor change in the SDS-PAGE mobility was observed by incubation of the RP with 1.0 mM UDPG or ADPG. Serine and threonine were not involved in a glucose linkage to protein, judging from the stability of the RP to a b-elimination treatment. The incorporated glucose was not released from RP by digestion with a-amylase, amyloglucosidase or phosphorylase.
