A comparative analysis of the citrate permease P mRNA stability in Lactococcus lactis biovar diacetylactis and Escherichia coli

The role of ribonucleases in the control of gene expression remains unknown in lactic acid bacteria. In the present work, we analysed the expression o f the citP gene, which encodes the lactococcal citrate permease P, through the stability of the citQRP messenger in both Lactococcus lactis biovar dia cetylactis (L. diacetylactis) and Escherichia coil. The chemical half-life for citQRP mRNA observed in L. diacetylactis wild-type strain was abnormall y long for bacteria. It was even longer than that detected in E, coli RNase E or RNase III mutant strains. A model of processing and fate of RNA speci es containing citP gene is presented. (C) 1999 Federation of European Micro biological Societies. Published by Elsevier Science B.V. All rights reserve d.