Activates the expression of pucFG, pucH, pucI, pucJKLM and guaD, while it represses pucABCDE and its own expression. Expression is very low in excess nitrogen (glutamate plus ammonia) and is induced during limiting-nitrogen conditions (glutamate). Expression slightly decreases when allantoin is added during limiting-nitrogen conditions. Belongs to the CdaR family.