taken together with the observation that phosphorylation of s7 occurs only when the cells are starved in buffers containing sodium chloride or high concentrations of tris , non-essential ions for normal growth , our data suggest that this protein modification is required to maintain the functional integrity of the ribosomes in an altered electrostatic environment , induced by changes in the extracellular ionic conditions .
C0007634
cells
C0035553
ribosomes