Autoregulation of the biosynthesis of the CcpA-like protein, PepR1, in Lactobacillus delbrueckii subsp bulgaricus

PepR1 from Lactobacillus delbrueckii subsp bulgaricus (Lb. bulgaricus) is involved in biosynthesis regulation of the prolidase PepQ. In this paper, we demonstrated that Lb. bulgaricus PepR1 biosynthesis is not constitutive like those of several bacteria but is auto-regulated and depends on the glucose concentration of the culture medium. We propose a model for PepQ regulation by PepR1.