Activity of stringent protein in ribosomes of Escherichia coli during the growth cycle

Abstract

To investigate whether the stringent protein in Escherichia coli was lost from ribosomes at certain phase of growth as in other organisms (Bacillus subtilis, mouse embryo), cells growing at various phases of the growth cycle were harvested and ribosomes tested for activity. The results showed that in E. coli, stringent protein was associated with the ribosomes throughout the growth cycle. The peak activity for the synthesis of guanosine tetra- and pentaphosphates appeared around midlogarithmic phase.