The invention relates to methods and means for regulating gene expression and to CodY target sequences. CodY represses its target genes by binding to specific DNA sequences upstream of the respective genes. A conserved target site was identified by analyzing upstream sequences of derepressed genes in a delta codY L. lactis MG1363 derivative, as identified in a DNA micro-array study. Also, CodY target sequences from other gram-positive bacteria, like B. subtilis and Streptococcus are disclosed. Hence, the invention provides CodY target sequences that may be used in different applications to repress or derepress gene expression.