P II -Regulated Arginine Synthesis Controls Accumulation of Cyanophycin in Synechocystis sp. Strain PCC 6803

Abstract
Cyanophycin (multi-l-arginyl-poly-l-aspartic acid) is a nitrogen storage polymer found in most cyanobacteria and some heterotrophic bacteria. The cyanobacterium Synechocystis sp. strain PCC 6803 accumulates cyanophycin following a transition from nitrogen-limited to nitrogen-excess conditions. Here we show that the accumulation of cyanophycin depends on the activation of the key enzyme of arginine biosynthesis, N-acetyl-l-glutamate kinase, by signal transduction protein PII.