CdbA is a DNA-binding protein and c-di-GMP receptor important for nucleoid organization and segregation in Myxococcus xanthus

Nat Commun. 2020 Apr 14;11(1):1791. doi: 10.1038/s41467-020-15628-8.


Cyclic di-GMP (c-di-GMP) is a second messenger that modulates multiple responses to environmental and cellular signals in bacteria. Here we identify CdbA, a DNA-binding protein of the ribbon-helix-helix family that binds c-di-GMP in Myxococcus xanthus. CdbA is essential for viability, and its depletion causes defects in chromosome organization and segregation leading to a block in cell division. The protein binds to the M. xanthus genome at multiple sites, with moderate sequence specificity; however, its depletion causes only modest changes in transcription. The interactions of CdbA with c-di-GMP and DNA appear to be mutually exclusive and residue substitutions in CdbA regions important for c-di-GMP binding abolish binding to both c-di-GMP and DNA, rendering these protein variants non-functional in vivo. We propose that CdbA acts as a nucleoid-associated protein that contributes to chromosome organization and is modulated by c-di-GMP, thus revealing a link between c-di-GMP signaling and chromosome biology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism*
  • Base Sequence
  • Cell Nucleus / metabolism*
  • Chromosome Segregation*
  • Chromosomes, Bacterial / metabolism
  • Cyclic GMP / analogs & derivatives*
  • Cyclic GMP / metabolism
  • DNA, Bacterial / metabolism
  • DNA-Binding Proteins / metabolism*
  • Genetic Loci
  • Models, Molecular
  • Myxococcus xanthus / metabolism*
  • Protein Multimerization
  • Protein Structure, Secondary
  • Transcription, Genetic


  • Bacterial Proteins
  • DNA, Bacterial
  • DNA-Binding Proteins
  • bis(3',5')-cyclic diguanylic acid
  • Cyclic GMP