Structural analysis of the GGDEF-EAL domain-containing c-di-GMP receptor FimX.
Navarro, M.V., De, N., Bae, N., Wang, Q., Sondermann, H.(2009) Structure 17: 1104-1116
- PubMed: 19679088 
- DOI: https://doi.org/10.1016/j.str.2009.06.010
- Primary Citation of Related Structures:  
3HV8, 3HV9, 3HVA, 4J40 - PubMed Abstract: 
Bacterial pathogenesis involves social behavior including biofilm formation and swarming, processes that are regulated by the bacterially unique second messenger cyclic di-GMP (c-di-GMP). Diguanylate cyclases containing GGDEF and phosphodiesterases containing EAL domains have been identified as the enzymes controlling cellular c-di-GMP levels, yet less is known regarding signal transmission and the targets of c-di-GMP. FimX, a protein from Pseudomonas aeruginosa that governs twitching motility, belongs to a large subfamily containing both GGDEF and EAL domains. Biochemical and structural analyses reveals its function as a high-affinity receptor for c-di-GMP. A model for full-length FimX was generated combining solution scattering data and crystal structures of the degenerate GGDEF and EAL domains. Although FimX forms a dimer in solution via the N-terminal domains, a crystallographic EAL domain dimer suggests modes for the regulation of FimX by c-di-GMP binding. The results provide the structural basis for c-di-GMP sensing via degenerate phosphodiesterases.
Organizational Affiliation: 
Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.