Structure of Bef3--Modified Response Regulator Pled: Implications for Diguanylate Cyclase Activation, Catalysis, and Feedback Inhibition
Wassmann, P., Chan, C., Paul, R., Beck, A., Heerklotz, H., Jenal, U., Schirmer, T.(2007) Structure 15: 915
- PubMed: 17697997 
- DOI: https://doi.org/10.1016/j.str.2007.06.016
- Primary Citation of Related Structures:  
2V0N - PubMed Abstract: 
Cyclic di-guanosine monophosphate (c-di-GMP) is a ubiquitous bacterial second messenger involved in the regulation of cell surface-associated traits and persistence. We have determined the crystal structure of PleD from Caulobacter crescentus, a response regulator with a diguanylate cyclase (DGC) domain, in its activated form. The BeF(3)(-) modification of its receiver domain causes rearrangement with respect to an adaptor domain, which, in turn, promotes dimer formation, allowing for the efficient encounter of two symmetric catalytic domains. The substrate analog GTPalphaS and two putative cations are bound to the active sites in a manner similar to adenylate cyclases, suggesting an analogous two-metal catalytic mechanism. An allosteric c-di-GMP-binding mode that crosslinks DGC and an adaptor domain had been identified before. Here, a second mode is observed that crosslinks the DGC domains within a PleD dimer. Both modes cause noncompetitive product inhibition by domain immobilization.
Organizational Affiliation: 
Core Program of Structural Biology and Biophysics, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland.