We show that the nitrogen regulatory protein GlnR of Lactococcus lactis represses transcription of the amtB-glnK, glnRA, and glnPQ operons. This likely occurs through a conserved DNA motif, 5'-TGTNA-7N-TNACAT-3', and takes place in response to extracellular glutamine and ammonium. GlnR-independent repression of amtB-glnK is mediated by the pleiotropic nitrogen regulator CodY.