Supplementary file 1_DUF4004 protein BacR (YhbD) of Bacillus subtilis is a regulator of bactofilin expression and interacts with bactofilins in a switch-like manner.docx

The only characterized member was shown to act as transcriptional repressor of genes involved in metabolism in Clostridium acetobutylicum. We have characterized the B. subtilis member of this protein family, encoded by the yhbD gene.

The absence of yhbD negatively affects the expression of the yhbDEF operon, and thereby of bactofilin genes, but does not show any other alteration of genome-wide transcript levels.</p>Results<p>We propose to name the protein as “BacR” for bactofilin regulator. The putative transcription factor binds to DNA in vitro, and forms predominantly dimers. Interestingly, purified bactofilins BacE and BacF bind to BacR in vitro, and strongly reduce its DNA binding, and the depletion of bactofilins leads to reduced copy numbers of BacR.