furB knockout

We used DNA microarrays to define the M. tuberculosis FurB regulon. For this porpouse we constructed a M. tuberculosis strain where furB was disrupted and its transcriptional profile was compared on DNA microarray with the transcriptional profile of its parental strain (H37Rv). A total of 32 genes included in 16 putative transcription units were shown to be up-regulated in the mutant relative to H37Rv. No repressed genes were identified. Seven representative genes were chosen from the microarray experiments and their expression was measured by quantitative RT-PCR using sigA as invariant internal control. In support to the gene expression profiling data, the mRNA levels of all selected genes was clearly higher in the furB mutant strain relative to H37Rv Keywords: comparative genomic hybridization Hybridizations were performed using RNA extracted from three different biological samples. Each sample was hybridized twice through reverse labelling of the respective cDNAs.