Figure 1

Overview of iron-responsive and Fur-regulated genes in C. crescentus identified by microarray analyses. The Venn diagrams were constructed using the number of up- and down-regulated genes from experiments comparing wild type cells exposed to iron-limiting versus iron-replete conditions or comparing fur mutant strain versus wild type strain both in iron-replete condition. The complete set of the genes belonging to each group is listed in Tables 1, 2, 3, 4 and Additional file 1: Table S1. The upstream region of these genes (−200 to +50 bp relative to the start codon) were searched for sequence motifs using the MEME tool. A 19-pb palindromic motif, corresponding to the Fur binding site, was exclusively found in the group of genes regulated by both iron and Fur.