Mutation of the cysteine residues that coordinate the WhiB [4Fe-4S] cluster prevents in vivo DNA binding by both WhiB and WhiA

The purpose of this experiment was to show that the iron-sulphur cluster ([4Fe-4S]) of whiB is essential for the DNA binding by WhiB and WhiA. The \"serine version of whiB\" mentioned below is a whiB in which the 4 cysteine residues which coordinate the [4Fe-4S] cluster were mutated to serines. ChIP-Seq using anti-FLAG anitbodies was performed in the following: 1. A whiB deletion strain expressing the FLAG-tagged serine version of WhiB (WhiBFLAG-Ser). 2. A whiB and whiA deletion strain expressing the FLAG-tagged serine version of WhiB (delAB_WhiBFLAG-Ser). 3. A whiB and whiA deletion strain expressing the serine version of WhiB and FLAG-tagged whiA (delAB_WhiAFLAG_WhiBcomp-Ser).