Hfq-dependent alteration of the S. meliloti transcriptome and proteome. Differentially expressed transcripts (upper graphs) and proteins (lower graphs) in the S. meliloti hfq knock-out mutants. Histograms show the number of differentially expressed genes and their distribution in the three S. meliloti replicons: chromosome (Chrom.), pSymA and pSymB. The distribution of annotated ORFs in the genome is indicated as reference. The adscription of these genes to functional categories according to the KEGG and S. meliloti databases is shown to the right in circle charts (see text for web pages of the referred databases). In brackets the number of genes belonging to each category.