THE ACCUMULATION OF PHOSPHORYLATED GUANOSINE NUCLEOTIDES IN ANABAENA CYLINDRICA.

Two highly phosphorylated guanosine derivatives accumulate in alkaline cultures of Anabaena cylindrica during the early stationary phase and in anaerobic, nitrogen-deprived cultures. The accumulation of these nucleotides is accompanied by the suppression of the normal accumulation of ppGpp and ppGppp, nucleotides which are effectors of the stringent response in bacteria. The accumulation of the two sets of nucleotides appears to be mutually exclusive. The accumulation of the guanosine derivatives during growth inhibition and their replacement of ppGpp and pppGpp suggests that the newly discovered guanine compounds may also fulfil a regulatory role.