Biofilms are aggregates of bacteria on a surface often associated with increased resistance to antibiotics and stress. In Vibrio cholerae, the bacterial species that causes cholera, biofilm formation is promoted by the bacterial second messenger cyclic di-guanosine monophosphate (c-di-GMP) and involves the transcription regulator VpsT. Krasteva et al. show that VpsT is itself a receptor for c-di-GMP and that binding of the small signaling molecule promotes VpsT dimerization, which is required for DNA recognition and transcriptional regulation. As well as activating components of the biofilm pathway, VpsT also down-regulates motility genes in a c-di-GMP–dependent manner.
P. V. Krasteva, J. C. N. Fong, N. J. Shikuma, S. Beyhan, M. V. A. S. Navarro, F. H. Yildiz, H. Sondermann, Vibrio cholerae VpsT regulates matrix production and motility by directly sensing cyclic di-GMP. Science 327, 866–868 (2010). [Abstract] [Full Text]