A locus containing the clpP and clpL genes in the lactic acid bacterium Oenococcus oeni was studied. Real-time reverse transcription-PCR analysis revealed different induction factors involved in expression of these genes during stress. According to the conditions, clpP and clpL genes could be transcripted as two distinct transcripts or cotranscripted. The clpP promoter depended on the CtsR regulator, but surprisingly the clpL promoter did not. The amount of the clpL transcript depended on mRNA stability. This clp ATPase gene is at least controlled at the posttranscriptional level.